Select all that apply. If x^2+b/ax+c/a=0 ; then: The sum of its roots = -b/a? The difference of its roots =-b/a? The product of its roots = c/a?The division of its roots = c/a? I can select multiple.
Answers
Answer:
The first and the thirdStep-by-step explanation:
[tex]x^2+\frac bax+\frac ca=0\\\\ ax^2+bx+c=0\\\\x_1=\dfrac{-b-\sqrt{b^2-4ac}}{2a}\qquad\quad x_2=\dfrac{-b+\sqrt{b^2-4ac}}{2a}\\\\\\x_1+x_2=\dfrac{-b-\sqrt{b^2-4ac}}{2a}+\dfrac{-b+\sqrt{b^2-4ac}}{2a}=\dfrac{-2b}{2a}=\dfrac{-b}a\\\\\\x_1\cdot x_2=\dfrac{-b-\sqrt{b^2-4ac}}{2a}\cdot\dfrac{-b+\sqrt{b^2-4ac}}{2a}=\\\\{}\ \ =\dfrac{b^2-b\sqrt{b^2-4ac}+b\sqrt{b^2-4ac}-(\sqrt{b^2-4ac})^2}{2a}=\dfrac{b^2-(b^2-4ac)}{4a^2}=\\\\{}\ \ =\dfrac{b^2-b^2+4ac}{4a^2}=\dfrac{4ac}{4a^2}=\dfrac{c}{a}[/tex]
[tex]x_1-x_2=\frac{-b-\sqrt{b^2-4ac}}{2a}-\frac{-b+\sqrt{b^2-4ac}}{2a}=\frac{-2\sqrt{b^2-4ac}}{2a}=\frac{-\sqrt{b^2-4ac}}{a}\\\\\\x_1\div x_2=\frac{-b-\sqrt{b^2-4ac}}{2a}\div\frac{-b+\sqrt{b^2-4ac}}{2a}=\frac{-b-\sqrt{b^2-4ac}}{2a}\,\cdot\,\frac{2a}{-b+\sqrt{b^2-4ac}}=\\\\=\frac{-b-\sqrt{b^2-4ac}}{-b+\sqrt{b^2-4ac}}=\frac{b+\sqrt{b^2-4ac}}{b-\sqrt{b^2-4ac}}=\frac{b^2+2\sqrt{b^2-4ac}+b^2-4ac}{b^2-b^2+4ac}=\frac{2b^2+2\sqrt{b^2-4ac}-4ac}{4ac}=[/tex]
[tex]=\frac{b^2+\sqrt{b^2-4ac}-2ac}{2ac}[/tex]
Related Questions
1. A test-tube has a diameter of 3cm. How many turns would a piece of thread of length
90.42cm make round the test tube. (Taken= =).
(3marks)
Answers
So if we think of a test tube, it looks sort of like a cylinder. This means that its cross-section would be a circle. To find out how many turns a piece of thread would make around the test tube, we need to find the circumference of the test tube, then divide the length of the string by the circumference.
Step 1) Find the circumference
C = pi x diameter
C = 3.14 x 3
C = 9.42
Step 2) Divide the length of the string by the circumference
90.42 / 9.42 = 9.5987
The string would make approximately 9.60 turns around the test tube.
Hope this helps!! :)
Please answer this in two minutes
Answers
Answer:
u = [tex]\sqrt{6}[/tex].
Step-by-step explanation:
This is a 45-45-90 triangle.
That means that there are two side lengths with lengths of x, and a hypotenuse with a length of xsqrt(2). We can then set up a proportion.
[tex]\frac{1}{\sqrt{3} } =\frac{\sqrt{2} }{u}[/tex]
1 * u = [tex]\sqrt{3} * \sqrt{2}[/tex]
u = [tex]\sqrt{6}[/tex].
Hope this helps!
The director of admissions at Kinzua University in Nova Scotia estimated the distribution of student admissions for the fall semester on the basis of past experience. Admissions Probability 1,100 .2 1,400 .3 1,300 .5 Click here for the Excel Data File What is the expected number of admissions for the fall semester? Compute the variance and the standard deviation of the number of admissions. (Round your standard deviation to 2 decimal places.)
Answers
Answer:
Variance =10900.00
Standard deviation=104.50
Step by step Explanation:
Admissions Probability for 1100= 0.2
Admissions Probability for 1400=0.3
Admissions Probability for 1300 =0.5
To find the expected value, we will multiply each possibility by its probability and then add.
mean = 1100*0.2 + 1400*0.3 + 1300*0.5 = 1290
To find the variance, we will start by squaring each possibility and then multiplying it by its probability. We will then add these and subtract the mean squared.
E(X^2)=( 1100²*0.2)+ (1400²*0.3 )+ (1300²*0.5) = 1675000
Variance(X)=E(X²)- [E(X)]²
= 1675000 - (1290)²
=10900
Hence, the Variance(X)=10900
Then to calculate the standard variation , we will use the formular below,
standard variation (X)=√ var(X)= √10900
=104.5
Hence the standard variation=104.5
HELLLPPPP I need a explication on whether or not these angle relationships are possible
Answers
Answer:
Step-by-step explanation:
5x+30 is a corresponding angle with 4x-9 so set them equal to each other. 4x-9+2x+3 will equal 180
Answer:
no, the values would be above 180º
Step-by-step explanation:
if...
(4x - 9) + (2x + 3) + y = 180
(5x + 30) + y = 180
then...
(4x - 9) + (2x + 3) = 5x + 30
so...
6x - 6 = 5x + 30
x = 36
plug it in.
4(36) - 9 = 135
2(36) + 3 = 75
already you can see the sum of these two angles surpasses 180 which is not possible for a triangle.
BRAINLIEST, 5 STARS, THANKS AND 100 POINTS IF ANSWERED BOTH CORRECTLY. --------------------- Which function rule describes the pattern in the table? X: -2, -1, 0, 1, 2 Y: 3, 2, 1, 0, -1 A) y = x + 1 B) y = x - 1 C) y = -x + 1 D) y = -x - 1 --------------------- Which function rule describes the pattern in the table? X: -2, -1, 0, 1, 2 Y: 14, 11, 8, 5, 2 A) y = 3x + 8 B) y = -3x - 8 C) y = 3x - 8 D) y = -3x + 8 -------------------- Thank you if you answered both correctly!
Answers
Answer:
1: C) y = -x + 1
2: D) y = -3x + 8
Step-by-step explanation:
Well number 1,
c is the correct option because,
-2 -> 2
2+1 - 3
This rule applies for all the x values.
2,
X: -2, -1, 0, 1, 2
Y: 14, 11, 8, 5, 2
d is the correct option because -3*-2 is 6 + 8 = 14.
this rule applies for all x values.
Thus,
the answers are C and D.
Hope this helps :)
The surface area of a solid is 10 square feet. The dimensions of a similar solid are
three times as great as the first. The surface area of the new solid in square feet
is...
PLEASE urgent
Answers
Answer:
90 ft²
Step-by-step explanation:
Given the sides of similar figures in the ratio a : b, then
ratio of areas = a² : b²
Here ratio of sides = 1 : 3 , thus
ratio of areas = 1² : 3² = 1 : 9
That is the surface area of the new solid is 9 times the first
SA = 9 × 10 = 90 ft²
The total surface area of the new solid in square feet is 90 square feet
Let the solid be a cube.
The surface area of a cube = 6L²
L is the length o the cube;
If the surface area of a solid is 10 square feet, then;
10 = 6L²
L² = 10/6
L = √10/6
If the dimensions of a similar solid are three times as great as the first, then;
New length Ln = 3√10/6
Total surface area of the new solid = 6Ln²
Total surface area of the new solid = 6(3√10/6)²
Total surface area of the new solid = 6(9*10/6)
Total surface area of the new solid = 6(90/6)
Total surface area of the new solid = 90 square feet
This shows that the total surface area of the new solid in square feet is 90 square feet
Learn more here: https://brainly.com/question/23756628
Carter bought a bear and paid for a football uniform. The total cost was $38.50. Write and solve an equation to find the cost, x, of buying a bear.
Answers
Answer:
Equation:- [tex]x + y = 38.50[/tex]
Solution of x:- [tex]x = 38.50 - y[/tex]
Step-by-step explanation:
Given
Total Purchase = $38.50
Required
Determine the equation for finding the cost of a bear
From the question; we understand that the cost of 1 bear is represented with x
Solving further; by representing the cost of 1 football uniform with y
So;
[tex]1\ bear + 1\ uniform = 38.50[/tex]
Substitute x for 1 bear and y for 1 uniform to give us an equation
[tex]x + y = 38.50[/tex]
Solving for x (Subtract y from both sides)
[tex]x +y - y = 38.50 - y[/tex]
[tex]x = 38.50 - y[/tex]
The equation can't be solved further
Solve the equation using the zero-product property. (2x − 8)(7x + 5) = 0 x = –2 or x = 7 x = –4 or x = x = 4 or x = x = 4 or x =
Answers
Answer:
x = 4 or x = - [tex]\frac{5}{7}[/tex]
Step-by-step explanation:
Given
(2x - 8)(7x + 5) = 0
Equate each factor to zero and solve for x
2x - 8 = 0 ⇒ 2x = 8 ⇒ x = 4
7x + 5 = 0 ⇒ 7x = - 5 ⇒ x = - [tex]\frac{5}{7}[/tex]
If point Q is reflected across x = 1, what are the coordinates of its reflection image?
Answers
Answer:
(-1, -2) last answer
Step-by-step explanation:
x = 1 is a vertical line
Answer:
(-1, -2)
Step-by-step explanation:
This is because the x-coordinate goes 2 units left to the line x = 1 and the y-coordinate remains the same.
I need help!
- 7(x + 2) = 21
Answers
Answer:
x = -5
Step-by-step explanation:
-7(x + 2) = 21
Divide each side by -7
-7/-7(x + 2) = 21/-7
x+2 = -3
Subtract 2 from each side
x+2-2 = -3-2
x = -5
Answer:
x = -5
Step-by-step explanation:
distribute: -7x-14 = 21
add 14 to both sides
divide by -7
x = -5
An annual salary is $45000. His tax free allowances total $13000. He has to pay a tax of 20% on his taxable income.
The tax payable is?
Answers
Answer:
6400
Step-by-step explanation:
Taxable amount=45000-13000=32000
tax=32000*20/100
=6400
please solve this using quadratic formula :")
Answers
Answer:
Step-by-step explanation:
The given equation is expressed as
(x + 1)/(x - 1) - (x - 1)/(x + 1) = 7/12
Simplifying the right hand side of the equation, it becomes
[(x + 1)(x + 1) - (x - 1)(x - 1)]/(x - 1)(x + 1)
x² + x + x + 1 - (x² - 2x + 1)/(x - 1)(x + 1)
(x² + 2x + 1 - x² + 2x - 1)/(x - 1)(x + 1)
4x/(x - 1)(x + 1)
Therefore,
4x/(x - 1)(x + 1) = 7/12
Cross multiplying, it becomes
4x × 12 = 7(x - 1)(x + 1)
48x = 7(x² + x - x - 1)
48x = 7x² - 7
7x² - 48x - 7 = 0
Applying the quadratic formula,
x = - b ± √(b² - 4ac)]/2a
from our equation,
b = - 48
a = 7
c = - 7
Therefore
x = [- - 48 ± √(- 48² - 4(7 × - 7)]/2 × 7)
x = [48 ± √(2304 + 196]/14
x = (48 ± √2500)/14
x = (48 ± 50)/14
x = (48 + 50)/14 or x = (48 - 50)/14
x = 98/14 or x = - 2/14
x = 7 or x = - 1/7
Answer: The given equation is expressed as (x + 1)/(x - 1) - (x - 1)/(x + 1) = 7/12Simplifying the right hand side of the equation, it becomes[(x + 1)(x + 1) - (x - 1)(x - 1)]/(x - 1)(x + 1)x² + x + x + 1 - (x² - 2x + 1)/(x - 1)(x + 1)(x² + 2x + 1 - x² + 2x - 1)/(x - 1)(x + 1)4x/(x - 1)(x + 1)Therefore, 4x/(x - 1)(x + 1) = 7/12Cross multiplying, it becomes4x × 12 = 7(x - 1)(x + 1)48x = 7(x² + x - x - 1)48x = 7x² - 77x² - 48x - 7 = 0Applying the quadratic formula,x = - b ± √(b² - 4ac)]/2a from our equation, b = - 48a = 7c = - 7Thereforex = [- - 48 ± √(- 48² - 4(7 × - 7)]/2 × 7)x = [48 ± √(2304 + 196]/14x = (48 ± √2500)/14x = (48 ± 50)/14x = (48 + 50)/14 or x = (48 - 50)/14x = 98/14 or x = - 2/14x = 7 or x = - 1/7
Step-by-step explanation:
URGENT PLEASE HELP
1. Use the rules of divisibility to check which of the following
numbers are multiples of (are divisible by) 2,3,4,5,6, 8, 9 and 10
a) 552
b) 315
c) 620
d) 426
Answers
b) 315 is a multiple of 3, 5 and 9
c) 620 is a multiple of 2, 4, 5 and 10
d) 426 is a multiple of 2 and 3
Rules include:
Even numbers are divisible by 2.
If the sum of a number’s digits are divisible by 3, the number is divisible by 3.
Any number ending in 5 or 0 is divisible by 5.
Any number divisible by both 2 and 3 is divisible by 6.
If the sum of a number’s digits are divisible by 9, the number is divisible by 9.
If a number ends in 0, it is divisible by 10.
If approximately 10% of people are left-handed, how many lefties would you expect in a high school graduating class of 424
Answers
Answer:
42
Step-by-step explanation:
P(left) = 0.10
Expected number of lefties among high school grads of 424
= 424 * 0.10
= 42 (to the nearest person)
Answer:
you do 20% of 424
1 0% of 424 =42.4
you could round it to 42
Please answer this in two minutes
Answers
Answer:
R = 21.8° to the nearest tenth
Step-by-step explanation:
To find Angle R we use tan
tan ∅ = opposite / adjacent
From the question
The opposite is 2
The adjacent is 5
So we have
tan R = 2/5
R = tan-¹ 2/5
R = 21.8° to the nearest tenthHope this helps you
Please please help me
Answers
Answer:
A = 189 cm²Step-by-step explanation:
The area of a parallelogram is equal to the product of the length of its side and the height of the parallelogram perpendicular to that side.
H = 9 cm
S = 21 cm
A = S•H = 21 cm • 9 cm = 189 cm²
A sphere has a diameter of 12 ft. What is the volume of the sphere? Give the exact value in terms of pi
Answers
Answer:
288π
Step-by-step explanation:
V=4 /3πr^3 is the formula. We have the diameter, so the radius is half (6). We now have V=4 /3π(6)^3 = 4/3π216 = 288π.
Your math teacher caught you text messaging in class, again, so the teacher is making you give a presentation to your math class next week. Your assignment is to analyze the scatter plot that shows people's ages and the number of text messages sent in a day. In 3-5 sentences, explain what you see in the scatter plot below.
Answers
Answer: If a scatterplot is included in the assignment
The dots plotted on the graph might closely follow the graph of exponential decline. There is a large number of texts per day by 19-20-21 year-olds, but the number seems to decline exponentially as age increases. With a little work, it may be possible to plot the curve and write an equation to model the decline.
Step-by-step explanation: Look at some graphs of exponential decay. Also consider harmonic and hyperbolic decay. The trend in the data is evident. The main challenge is to look at the data and create an equation that models it.
On a coordinate plane, a graph shows Street on the x-axis and Avenue on the y-axis. A line is drawn from Tia to Lei. Tia is at (4, 8) and Lei is at (12, 20). Tia lives at the corner of 4th Street and 8th Avenue. Lei lives at the corner of 12th Street and 20th Avenue. The fruit market is Three-fourths the distance from Tia’s home to Lei's home.
Answers
Answer:
(10, 17)
Step-by-step explanation:
It might be easier to explain with a picture or drawing, but I am new to this, so I would try using words.
Assuming the fruit market is on that straight line from Tia's home to Lei's, So we look at both address (coordinates)
From Tia to Lei, x coordinate is from 4 to 12, that's increased by 8, divide by 4, one step is 2.
y coordinate is from 8 to 20, an increase of 12, divide by 4 again, one step is 3.
The fruit market is at 3/4 distance, so 3 steps, on both x and y coordinates.
x: 4+6 = 10
y: 8+9=17
The fruit market is at point (10,17)
What is graph?
A graph can be defined as a pictorial representation or a diagram that represents data or values.
The point (x,y) which divides the segment AB with endpoints at A(x₁,y₁) and B(x₂,y₂) in ratio m:n has cordinates
[tex]x= \dfrac{nx_1+nx_2}{m+n}[/tex]
[tex]y= \dfrac{ny_1+ny_2}{m+n}[/tex]
Tia is at P(4, 8) and Lei is at Q(12, 20).
The fruit market (F) is three-fourths the distance from Tia’s home to Lei's home, then PM : PQ = 3:4 or PM : MQ = 3:1
So,
[tex]x= \dfrac{1.4+3.12}{3+1} = \dfrac{4+36}{4} = \dfrac{40}{4} = 10 \\y= \dfrac{1.8+3.20}{3+1} = \dfrac{8+60}{4} = \dfrac{68}{4} = 17[/tex]
Hence, the fruit market is at point (10,17) which means it is placed at the corner of 10th Street and 17th Avenue.
Learn more about graph here:
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#SPJ5
Simplify.
N4 x N7 over n5
Answers
Answer:
[tex]n^6[/tex].
Step-by-step explanation:
[tex]n^4 * \frac{n^7}{n^5}[/tex]
= [tex]n^4 * n^{7 - 5}[/tex]
= [tex]n^4 * n^2[/tex]
= [tex]n^{4 + 2}[/tex]
= [tex]n^6[/tex].
Hope this helps!
Tom and Harry live 24km from each other, which on the map is 5 cm Given that the distance on the map between Harry and the Sea view is 4cm Find the actual distance between Harry and the Sea view.
Answers
Answer:
19.5 km
Step-by-step explanation:
the actual distance between Harry and the Sea view:
if 24 km is 5 cm on map
24*4/5= 19.5 km
Please answer in two minutes
Answers
Answer:
Toa
48/55
Step-by-step explanation:
O/A
48/55
Maya is interning at a law firm over the summer and is paid by the hour. If her hourly wage is $52, which equation represents the proportional relationship between the wages she earns (w) and the number of hours (h)?
Answers
Answer: w= 52h
Step-by-step explanation:
Given: Maya is interning at a law firm over the summer and is paid by the hour.
Her hourly pay = $52
i.e. She is paid $52 per hour.
Let the wages she earns is denoted by 'w' and the number of hours is denoted by 'h'.
Now, (Total wages earned) = (hourly pay) x (Number of hours)
w = (52) (h)
⇒ w= 52h
Hence, the equation represents the proportional relationship between the wages she earns (w) and the number of hours (h): w= 52h
Answer:52h
Step-by-step explanation: tried got it right
the sum of the first term of an ap is 240 and the sum of the next 4 term is 220 find the first term of the ap
Answers
Answer:
The common difference is -5/4
T(n) = T(0) - 5n/4,
where T(0) can be any number. d = -5/4
Assuming T(0) = 0, then first term
T(1) = 0 -5/4 = -5/4
Step-by-step explanation:
T(n) = T(0) + n*d
Let
S1 = T(x) + T(x+1) + T(x+2) + T(x+3) = 4*T(0) + (x + x+1 + x+2 + x+3)d = 240
S2 = T(x+4) + T(x+5) + T(x+6) + T(x+7) = 4*T(0) + (x+5 + x+6 + x+7 + x+8)d = 220
S2 - S1
= 4*T(0) + (x+5 + x+6 + x+7 + x+8)d - (4*T(0) + (x+1 + x+2 + x+3 + x+4)d)
= (5+6+7+8 - 1 -2-3-4)d
= 4(4)d
= 16d
Since S2=220, S1 = 240
220-240 = 16d
d = -20/16 = -5/4
Since T(0) has not been defined, it could be any number.
Write an equation for the line that is parallel to the given line and that passes through the given point. y=34x−9;(−8,−18)
Answers
Answer:
Step-by-step explanation:
eq. of line parallel to y=34x-9 is y=34 x+k
∵ it passes through (-8,-18)
∴-18=34×-8+k
k=-18+272
k=254
so reqd. eq. is y=34 x+272
The ratio of Ed's toy cars to Pete's toy cars was initially 5:2. After Ed gave 30 toy cars to Pete, they each had an equal number of cars. How many toy cars did they have altogether?
Answers
Answer:
140 toy cars
Step-by-step explanation:
The ratio of Ed's toy car to Pete's toy car is initially given as 5:2
Ed gave Pete a total number of 30 cars
Let x represent the greatest common factor that exists between both number
Number of Ed's car is represented as 5x
Number of Pete car is represented as 2x
Since they each have an equal number of cars which is 30 then we can solve for x as follows
5x-30=2x+30
Collect the like terms
5x-2x= 30+30
3x= 60
Divide both sides by the coefficient of x which is 3
3x/3=60/3
x=20
Ed's car is 5x, we substitute 20 for x
5(20)
= 100 cars
Pete car is 2x,we substitute 20 for x
2(20)
= 40 cars
Therefore, the total number of cars can be calculated as follows
= 100+40
= 140 toy cars
Hence they have 140 toy cars altogether
Answer:
140
Step-by-step explanation:
Which option is it??????
Answers
Answer:
both the equation and it's inverse are functions
NEED HELP ON THIS ASAP WEE WOO WEE WOO
Answers
Answer:
50
Step-by-step explanation:
hellpp plzzzzz.......
Answers
Answer:
120Step-by-step explanation:
Given
u = 14 , a = 8 , t = 4
Now, let's find the value of s
[tex]s = ut + \frac{1}{2} a {t}^{2} [/tex]
plug the values
[tex] = 14 \times 4 + \frac{1}{2} \times 8 \times {4}^{2} [/tex]
Reduce the numbers with G.C.F 2
[tex] = 14 \times 4 + 4 \times {4}^{2} [/tex]
Multiply the numbers
[tex] = 56 + 4 \times {4}^{2} [/tex]
Calculate the product
[tex] = 56 + {4}^{3} [/tex]
Evaluate the power
[tex] = 56 + 64[/tex]
Add the numbers
[tex] = 120[/tex]
Hope this helps..
best regards!!
Choose the equivalent system of linear equations that will produce the same solution as the one given below 4x-y=-11 2x+3y=5
Answers
Answer: x = -2 , y = 3
Step-by-step explanation:
4x-y=-11
2x+3y=5
Solve 4x-y=-11 for y
Add -4x to both sides
4x-y+-4x=-11+-4x
-y=-4x-11
Divide both sides by -1
-y/-1=-4x-11/-1
y=4x+11
Substitute 4x+11 for y in 2x +3y=5
2x+3y=5
2x+3(4x+11)=5
Simplify both sides of the equation
14x+33=5
Add -33 to both sides
14x+33+-33=5+-33
14x=-28
Divide both sides by 14
14x/14=-28/14
x=-2
Substitute -2 for x in y= 4x+11
y=4x+11
y=(4)(-2)+11
Simplify both sides of the equation
y=3