F (x) = x^2 + 4x; Find f (−7)

Answer:

-5

Step-by-step explanation:

When answering these problems, I like to think of dirt stacks. (Weird, but it helps.)

Okay, so you have a stack of dirt one foot off the ground. Then you dig six feet down, including the stack.  Because the stack will be 5 feet into the ground now, the answer is -5.

Answer:

b = 1/4

Step-by-step explanation:

We will use 4 as a common denominator.

3 × 2 = 6        2 × 2 = 4

Now we have the equation 6/4 + b = 7/4

Answer:

a= 38.85

Step-by-step explanation:

Answer:

[tex]\boxed {a = 38.85}[/tex]

Step-by-step explanation:

Solve for the value of [tex]a[/tex]:

[tex]\frac{a}{3.5} - 4.8 = 6.3[/tex]

-Add both sides by [tex]4.8[/tex]:

[tex]\frac{a}{3.5} - 4.8 + 4.8 = 6.3 + 4.8[/tex]

[tex]\frac{a}{3.5} = 11.1[/tex]

-Multiply both sides by [tex]3.5[/tex]:

[tex]a = 11.1 \times 3.5[/tex]

[tex]\boxed {a = 38.85}[/tex]

Therefore, the value of [tex]a[/tex] is [tex]38.85[/tex].

Step-by-step explanation:

(8x+6) (9x-30)

=72x²-240x+54x-180

=72x²-186-180

Answer:

(8x+6) (9x-30)

=72x²-240x+54x-180

=72x²-186-180

Step-by-step explanation:

Answer:

9.45 × 10⁵ pounds of steel

Step-by-step explanation:

Last year, Summerfield Steel sold 6.5×10⁴ pounds of steel to private businesses and 2.5×10⁵ pounds of steel to government agencies.

Total amount of steel sold last year = (6.5 × 10⁴ + 2.5 × 10⁵) pounds = 315000 pounds = 3.15 × 10⁵ pounds

This year, they expect to sell 3 times that amount.

This year = 3 × 3.15 × 10⁵ pounds

= 9.45 × 10⁵ pounds of steel

Answer:

BC = 40

Step-by-step explanation:

Answer:

X=23

BC = 40

Step-by-step explanation:

Answer:

the answer would be 20

Step-by-step explanation:

so if 18-(-2)=?

two nwgatives make a positive. So the equation would turn into 18+2=20

Im not 100% if this is right but htis is how I was taught to do it.

Answer:

Step-by-step explanat

Given=F(0) = 3 and f(1) = 15.

So f(X)=12x+3

When X=0, f(0)=12x0+3=3

When X=1, f(1) = 12x1+3= 15

So f(X)=12x+3 is the solution o

Step-by-step explanation:

if the area of a box is 1 cm^2

then area of triangle is6 cm square

Answer:

6x^2+10x-6=0

Step-by-step explanation:

First, you need to add all like terms:

6x^2+8x-6=-2x

Now move the -2x to the other side:

6x^2+10x-6=0

Answer:

x =(-5+√61)/6= 0.468

or:

x =(-5-√61)/6=-2.135

Step-by-step explanation:

Rearrange the equation by subtracting what is to the right of the equal sign from both sides of the equation :

                    6*x^2+8*x-6-(2-2*x-2)=0  

Step by step solution :

STEP 1 :

The Equation at the end of step 1

 (((2•3x2) +  8x) -  6) -  -2x  = 0  

STEP 2 :

STEP 3 :

Pulling out like terms

3.1     Pull out like factors :

  6x2 + 10x - 6  =   2 • (3x2 + 5x - 3)  

Trying to factor by splitting the middle term

3.2     Factoring  3x2 + 5x - 3  

The first term is,  3x2  its coefficient is  3.

The middle term is,  +5x  its coefficient is  5.

The last term, "the constant", is  -3  

Step-1: Multiply the coefficient of the first term by the constant   3 • -3 = -9  

Step-2: Find two factors of  -9  whose sum equals the coefficient of the middle term, which is   5.

     -9    +    1    =    -8  

     -3    +    3    =    0  

     -1    +    9    =    8  

Observation: No two such factors can be found !!

Conclusion: Trinomial can not be factored

The Equation at the end of step 3 :

 2 • (3x2 + 5x - 3)  = 0  

STEP 4 :

Equations which are never true:

4.1      Solve :    2   =  0

This equation has no solution.

A non-zero constant never equals zero.

Parabola, Finding the Vertex:

4.2      Find the Vertex of y = 3x2+5x-3

Parabolas have the highest or lowest point called the Vertex.   Our parabola opens up and accordingly has the lowest point (AKA absolute minimum).   We know this even before plotting  "y"  because the coefficient of the first term, 3, is positive (greater than zero).  

Each parabola has a vertical line of symmetry that passes through its vertex. Because of this symmetry, the line of symmetry would, for example, pass through the midpoint of the two x-intercepts (roots or solutions) of the parabola. That is if the parabola has indeed two real solutions.  

Parabolas can model many real-life situations, such as the height above ground, of an object thrown upward, after some period of time. The vertex of the parabola can provide us with information, such as the maximum height that an object, thrown upwards, can reach. For this reason, we want to be able to find the coordinates of the vertex.  

For any parabola, Ax2+Bx+C, the x -coordinate of the vertex is given by  -B/(2A). In our case, the  x  coordinate is  -0.8333  

Plugging into the parabola formula  -0.8333  for  x  we can calculate the  y -coordinate :  

 y = 3.0 * -0.83 * -0.83 + 5.0 * -0.83 - 3.0

or   y = -5.083

Parabola, Graphing Vertex, and X-Intercepts :

Root plot for :  y = 3x2+5x-3

Axis of Symmetry (dashed)  {x}={-0.83}  

Vertex at  {x,y} = {-0.83,-5.08}  

x -Intercepts (Roots) :

Root 1 at  {x,y} = {-2.14, 0.00}  

Root 2 at  {x,y} = { 0.47, 0.00}  

Solve Quadratic Equation by Completing The Square

4.3     Solving   3x2+5x-3 = 0 by Completing The Square.

Divide both sides of the equation by  3  to have 1 as the coefficient of the first term :

  x2+(5/3)x-1 = 0

Add  1  to both side of the equation :

  x2+(5/3)x = 1

Now the clever bit: Take the coefficient of  x, which is  5/3, divide by two, giving  5/6, and finally square it giving  25/36  

Add  25/36  to both sides of the equation :

 On the right-hand side we have :

  1  +  25/36    or,  (1/1)+(25/36)  

 The common denominator of the two fractions is  36   Adding  (36/36)+(25/36)  gives  61/36  

 So adding to both sides we finally get :

  x2+(5/3)x+(25/36) = 61/36

Adding  25/36  has completed the left-hand side into a perfect square :

  x2+(5/3)x+(25/36)  =

  (x+(5/6)) • (x+(5/6))  =

 (x+(5/6))2

Things which are equal to the same thing are also equal to one another. Since

  x2+(5/3)x+(25/36) = 61/36 and

  x2+(5/3)x+(25/36) = (x+(5/6))2

then, according to the law of transitivity,

  (x+(5/6))2 = 61/36

We'll refer to this Equation as  Eq. #4.3.1  

The Square Root Principle says that When two things are equal, their square roots are equal.

Note that the square root of

  (x+(5/6))2   is

  (x+(5/6))2/2 =

 (x+(5/6))1 =

  x+(5/6)

Now, applying the Square Root Principle to  Eq. #4.3.1  we get:

  x+(5/6) = √ 61/36

Subtract  5/6  from both sides to obtain:

  x = -5/6 + √ 61/36

Since a square root has two values, one positive and the other negative

  x2 + (5/3)x - 1 = 0

  has two solutions:

 x = -5/6 + √ 61/36

  or

 x = -5/6 - √ 61/36

Note that  √ 61/36 can be written as

 √ 61  / √ 36   which is √ 61  / 6

Solve Quadratic Equation using the Quadratic Formula

4.4     Solving    3x2+5x-3 = 0 by the Quadratic Formula.

According to the Quadratic Formula,  x, the solution for   Ax2+Bx+C  = 0, where  A, B,  and  C are numbers, often called coefficients, is given by :

           - B  ±  √ B2-4AC

 x =   ————————

                     2A

 In our case,  A   =     3

                     B   =    5

                     C   =   -3

Accordingly,  B2  -  4AC   =

                    25 - (-36) =

                    61

Applying the quadratic formula :

              -5 ± √ 61

  x  =    —————

                   6

 √ 61, rounded to 4 decimal digits, is   7.8102

So now we are looking at:

          x  =  ( -5 ±  7.810 ) / 6

Two real solutions:

x =(-5+√61)/6= 0.468

or:

x =(-5-√61)/6=-2.135

HOPE THIS HELPS!

PLEASE MARK BRAINLIEST IF THIS HELPED YOU LEARN! :)

Answer:

1: No, this is not direct variation

2: Yes, this is direct variation with k= 2.34

Step-by-step explanation:

I’m Just Built Different

Answer:

y-1 = -2(x-2) graph:

Answer:

Graph is below

Step-by-step explanation:

Graph the line using the slope and y-intercept, or two points.

Slope:

−

2

y-intercept:

(

0

,

5

)

x

y

0

5

5

2

0

Answer:

33(3+1)

Step-by-step explanation:

Find the GCF of 99 and 33

Factor 33 out

Answer:

y=1/2x+4

Step-by-step explanation:

change of x=2-(-4)=6

change of y=6-3=3

slope=3/6 or 1/2

y intercept=5

y=1/2x+5

Answer:

s^2 = r^2 + h^2.

Step-by-step explanation:

You need to know the radius of the base as well.

Then you use the Pythagoras theorem:

s^2 = r^2 + h^2     where r = radius and h = the height.

Answer:

a. sine StartFraction pi Over 3 EndFraction = StartFraction opposite Over hypotenuse EndFractionEquals StartFraction opposite Over 1 EndFraction  Equals opposite

The length opposite the angle is the vertical distance from the x-axis on the graph.

Step-by-step explanation:

sin (π/3) = opposite/hypotenuse = opposite/1; The length opposite the angle is the vertical distance from the x-axis on the graph.

Unit circle is a circle centered at the origin, (0,0) with radius(r) i.,e r= 1.

The angle π/3 forms an arc of length S and the x-axis and y-axis divide the coordinate plane and the unit circle as it is centered at (0.0).

Also, the terminal side intersect the circle at (x, y). Thus;

sin (π/3) = opposite/hypotenuse = opposite/1

Thus;

sin (π/3) = opposite

Also, the length opposite the angle is the vertical distance from the x-axis on the graph.

Read more about Unit circle at; https://brainly.com/question/4637991

Answer:

y = 50x + 200

Step-by-step explanation:

He has $200 at the bank. He is then adding 50 per month (that's why its 50x).

Answer:

$3.2

Step-by-step explanation:

so there's a strategy to do this its very helpful!

100%-$40

8%-x

~cross multiply~

100x=320

÷100     ÷100

________________

x=$3.2

Hope this helps :D

Answer:

7.87X10^3

Step-by-step explanation:

^ means to the power of

Answer:

5x + 22=

Step-by-step explanation:

8x+13-3x+9

Combine like terms.

8x-3x=5x

13+9=22

Piece it back together.

5x+22

And there you have it. Hope it helps! :3

Answer:

Step-by-step explanation:

5.00 for 2 loaves is $2.50 a loaf.

She wants 5 loaves for $12.50

5*2.50= $12.50 so she is correct.

Answer:

C. y = -2/3x -2

Step-by-step explanation:

We know the slope is negative. You can find slope using rise/run. The y-intercept is -2 because the line meets -2 at the y-intercept.    

Answer:

The first answer (top)

Step-by-step explanation:

Standard form is ax+by=c

a and b are the coefficients

Take a point from the given line

I chose (0, -2)

Then, plug in the values of x and y

2*0+3*-2=-6

-6=-6

Since it works the standard form of the line is 2x+3y=-6

Answer:

Point-slope form: y + 5 = 13/-4 (x-1)

Slope-intercept form:

Step-by-step explanation:

Ok, so first to find the equation in point-slope form, you need to find the slope. So, the slope would be 7- (-5)/-3-1 , which is 13/-4. That is your slope, or m. Now, for point-slope form, you have the equation y - y1 = 13/-4 (x-x1). Now, you take one of your points, say (1, -5), and you put it into the equation. So your point-slope form equation would be y - (-5) = 13/-4 (x - 1). This would simplify to y + 5 = 13/-4(x - 1).

Now for slope-intercept form, you have m, the slope, which is 13/-4. Substituting that into the equation, you have y = 13/-4x + b. To find b, you substitute one of your coordinates into the equation. For example, (1, -5). Then you have -5 = (13/-4 * 1) +b. Simplify this, and you have b = -5+ 13/-4, which is -20/4 + 13/-4, which is -20/4 - 13/4 = -33/4. So your final equation is y = 13/-4x - 33/4.

Hope that helped.

Answer: x = 2

Simplify and Distribute

(−5)(4x)+(−5)(−2)=(−2)(3)+(−2)(6x)

−20x+10=−6+−12x

−20x+10=−12x−6

Adding 12x both sides.

−20x+10+12x=−12x−6+12x

−8x+10=−6

Subtract 10 both sides

−8x+10−10=−6−10

-8x = -16

Then divide both sides by 8

-8x/8 = -16/8

x=2

Answer:

0.4

Step-by-step explanation:

Since there are 5 spaces between the 1 and 0, each tick represents [tex]\frac{1}{5}[/tex] or 0.2 units. Counting up from 0 you get 0.4

Answer:

Step-by-step explanation:

therefore, the answer is 0.4

Answer:

Bag 2

Step-by-step explanation:

Given

Bag 1:

[tex]14\ ounce = 3.50[/tex]

Bag 2:

[tex]24\ ounce = 5.28[/tex]

Required

Which is a better buy

To get which buy is better, we first get the unit price of each bag.

[tex]Unit\ Price = Amount/Size[/tex]

For bag 1:

[tex]Unit\ Price = 3.50/14[/tex]

[tex]Unit\ Price = 0.25[/tex]

For bag 2:

[tex]Unit\ Price = 5.28/24[/tex]

[tex]Unit\ Price = 0.22[/tex]

The best buy is the one with smaller unit price

Hence, bag 2 is better to buy