How would I simplify these expressions? (Pre-Calculus) I know that you are supposed to multiply all of these to do so, but every time I do that, I still get the wrong answer. My textbook says that these are the answers:
19: -15 + 8i
21: 8 + 6i
23: 34
25: 85
Could anyone explain how they got these answers? Mine are way off. Is the book just wrong? In #21, how would 3 times 3 equal 8 in the answer? Am I missing something?

Answer:

(-4,3)

Step-by-step explanation:

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Answer: y = (5/3)x + -1

Step-by-step explanation:

The slope is -5/3, so since its a reflection in the x - axis, the new slope would be the opposite, 5/3. Now for the +1, you just have to find the y intercept by plotting the dots at the opposite version of the y number that is already there. For example because the point (0,1) has 1 as its y number, you make it into -1, and for example if you have the point (3,-4) since -4 is the y number you change it to 4.

Answer:

10) x=9

11) x=25

Step-by-step explanation:

a triangle is 180º total

10)   2x+8x+90=180

10x=90

x=9

11) 3x+1+2x+2+2x+2=180

7x+5=180

7x=175

x=25

Answer:

5.45 then 6.454 then 5425 then 12825

Step-by-step explanation:

Answer:

w+w+5w = 7w

Step-by-step explanation:

Answer:

7w

Step-by-step explanation:

Answer:

4,0 is the right ok I am a professor

Answer:

$86.80

Step-by-step explanation:

Answer:

13.1

Step-by-step explanation:

Answer:

1

Step-by-step explanation:

Answer:

Let X be other interior opposite angle of a △XYZ.

Let Y be the third angle.

Exterior angle is equal to sum of interior opposite angles.

120

o

=30

o

+∠X

⇒∠X=90

o

Now, Sum of interior angles of a triangle is 180

o

⇒90

o

+30

o

+∠Y=180

o

⇒∠Y=180

o

−120

o

=60

o

Step-by-step explanation:

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Answer:

a+y≤1000 and 25a+12.50y>15000

Step-by-step explanation:

Answer:

y[tex]\geq[/tex]5

Step-by-step explanation:

7(2)-9

14-9

5

y[tex]\geq[/tex]5

Answer 2nd one

Step-by-step explanation:

Answer: I can't find the answer :(

B. (−2, −1)

Step-by-step explanation: I don't know :(

From when I am looking at the graph it looks like the answer would be

P= (-2, -1)

Q= (1, -2)

Answer:

24

Step-by-step explanation:

x-3=5, solve for x so that x=5+3

now put this in place of x in the expression 2(x+4)

2[(5+3)+4]

2(8+4)

2(12)

24

Answer:

[tex]a_n=-1+(n-1)(-2)[/tex]

Step-by-step explanation:

The arithmetic sequence formula looks like this:

[tex]a_n=a_1+(n-1)d[/tex]

where aₙ is the nth term, a₁ is the first term, n is the index, and d is the common difference.

Each consecutive term is decreased by 2 over the last, so d = 2. The first term is -1 of course, so you can write this equation:

[tex]a_n=-1+(n-1)(-2)[/tex]

Just to confirm:

[tex]a_n=-1+(n-1)(-2)\\a_3=-1+(2)(-2)\\a_3=-1-4\\a_3=-5[/tex]

And it works, -5 is the 3rd term in the sequence.

Answer:

[tex]a_{n}[/tex] = 1 - 2n

Step-by-step explanation:

The nth term of an arithmetic sequence is

[tex]a_{n}[/tex] = a₁ + (n - 1)d

where a₁ is the first term and d the common difference

Here a₁ = - 1 and d = a₂ - a₁ = - 3 - (- 1) = - 3 + 1 = - 2 , then

[tex]a_{n}[/tex] = - 1 - 2(n - 1) = - 1 - 2n + 2 = - 2n + 1 = 1 - 2n

Answer: 72.5%

Step-by-step explanation:

I used trial and error to figure this out.

I first found a quarter of 30 which is 7.5, so the percentage is near 75% since when 7.5 is times by 3 it becomes 22.5 which is close. Then I found what one is by dividing 30 by 100 and guessed the percentages getting closer to the answer basing on whether my last answer was to low or high and found 72.5% of 30 is 21.75 so the answer is 72.5%.

Using the binomial distribution, it is found that there is a 0.99999984 = 99.999984% probability that at least one household has a television set.

For each household, there are only two possible outcomes, either it has at least one television set, or it does not. The probability of a household having at least one television set is independent of any other household, which means that the binomial distribution is used to solve this question.

Binomial probability distribution

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]

The parameters are:

In this problem:

The probability that at least one household has a television set is:

[tex]P(X \geq 1) = 1 - P(X = 0)[/tex]

In which:

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

[tex]P(X = 0) = C_{4,0}.(0.98)^{0}.(0.02)^{4} = 0.00000016[/tex]

Then:

[tex]P(X \geq 1) = 1 - P(X = 0) = 1 - 0.00000016 = 0.99999984 [/tex]

0.99999984 = 99.999984% probability that at least one household has a television set.

A similar problem is given at https://brainly.com/question/24863377

Using linear system of equations, the cost tie is £7.43.

In everyday life, we can utilize linear equations to compare prices, make predictions, create budgets, and more. When all of the variables have a highest power of one, an equation is considered to be linear. Each variable is reliant on the others. A one-degree equation is another name for this kind of equation. Continue reading to learn how to solve a linear equation in one or two variables using its standard form, formula, graph, and rules.

Given,

Haala buys 13 identical shirts and 22 identical ties for £363.01 the cost of the shirt is £15.35,

According to question,

let cost of shirt = x

cost of tie = y

Now putting it in the equation,

13x + 22y = 363.01

given x = 15.35

⇒ y = 363.01 - 13(15.35) / 22

y = 363.01 - 199.55 / 22

y = 7.43

To learn more about linear system of equations from given link

https://brainly.com/question/25858757

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Answer:

25-10  (25 - A and 10 - B)

Step-by-step explanation:

25 - 10 equals the 15 point margin

25 plus 10 equals the 35 point score combined

Hope it helps

Answer:

4000

Step-by-step explanation: First multiply the first two equations and will give you 1200000000 divided by 300000. Now logically 12/3is 4  so u do the same in the equation and it gives you 4000. Pls give brainly if i was right

Answer:

Step-by-step explanation:

(1.2•10^9) divided by (3•10^5)

(1.2 * 10^9) : (3 * 10^5) =

(1.2 * 1000000000) : (3 * 100000) =

1200000000 : 300000 =

4000

Answer:

  13.05%

Step-by-step explanation:

The value of an ordinary annuity earning interest compounded annually is ...

  A = P((1 +r)^n -1)/r . . . . . interest rate r for n years on principal payments P

For this account, the balance after 5 years will be ...

  A = 3000((1 +.07)^5 -1)/0.07 = 3000·5.750739

The sum of payments is ...

  payment total = 3000·5

Then the amount of interest is ...

  3000·(5.750739 -5) = 3000·0.750739

and the fraction that is of the account balance is ...

  (3000·0.750739)/(3000·5.750739) × 100% ≈ 13.05%

About 13.05% of the balance is interest earned.

Answer:

78 + B = 91...

91 - 78 = B

91 - 78 = 13

B = 13

Step-by-step explanation:

Answer:

72.8325

Step-by-step explanation:

I think it is that

Answer:

18

Step-by-step explanation:

Answer:

30

Step-by-step explanation:

When estimating we round to the nearest 1.s.f

Thus...

608 rounded to the nearest 1sf

= 600

and....

23 rounded to the nearest 1sf

=20

Therefore- 600÷ 20 = 30

Hope this helped you- have a good day bro cya)

Answer:

If ΔPQR ≅ ΔTSR

Angles:

P and T

Q and S

R and R

Lines:

PQ and TS

QR and SR

PR and TR

[tex]slope = m = \cfrac{rise}{run} \implies \cfrac{ f(x_2) - f(x_1)}{ x_2 - x_1}\impliedby \begin{array}{llll} average~rate\\ of~change \end{array}\\\\[-0.35em] \rule{34em}{0.25pt}\\\\ f(x)=2x - 5 \quad \begin{cases} x_1=2\\ x_2=5 \end{cases}\implies \cfrac{f(5)-f(2)}{5-2}\implies \cfrac{[2(5)-5]~~ - ~~[2(2)-5]}{3} \\\\\\ \cfrac{5-(-1)}{3}\implies \cfrac{5+1}{3}\implies 2[/tex]

Answer:

Parallel lines: Line B and C

Perpendicular lines: Line A and B; Line A and C

Step-by-step explanation:

To answer this question, we only need to find the slope of each equation. The formula for slope is attached in a picture.

LINE A

Substituting the first line into the formula, we will get...

(2 - 5)/(0 -(-4))

-3/4

LINE B

Substituting the second line's points into the formula we will get...

(2 - 6)/(3 - 6)

-4/-3

4/3

LINE C

Substituting the third line's points into the formula we will get...

(3 -(-1)/(0 -(-3))

4/3

So, parallel lines have the same slope, right? Since line b and line c have the same slope, they are parallel.

And, perpendicular lines have negative reciprocal slopes, right? (reciprocal means x/y -> y/x) Since -3/4 and 4/3 are negative reciprocals of each other, they are perpendicular.

Therefore...

Parallel lines: Line B and C

Perpendicular lines: Line A and B; Line A and C

Answer:

f(x) = 3х + 1

Step-by-step explanation:

Answer:

[tex]2[/tex]

Step-by-step explanation:

Let [tex][n][/tex] denote the area of some polygon [tex]n[/tex].

The sum of the area of quadrilaterals BCDE and MNDE is equal to [tex][ABC]-([MBE]+[NDC]+AMN])[/tex] (big triangle subtracting the three smaller triangles that aren't part of BCDE or MNDE).

Let the area of triangle ABC be [tex]\alpha[/tex].

Triangle AMN is similar to triangle ABC. Because their side lengths are in ratio 1:2 respectively, the ratio of the area of triangle AMN to triangle ABC is [tex]1:2^2=1:4[/tex].

Therefore, [tex]\displaystyle [AMN]=\frac{1}{4}[ABC]=\frac{1}{4}\alpha[/tex].

Now for triangle NDC, NDC is similar to triangle AMC. Since M is the midpoint of AB, AMC is half the area of ABC. The ratio of the side lengths between triangle NDC and triangle AMC is [tex]1:2[/tex] because the D is the midpoint of MC, so it follows the ratio of their areas must be [tex]1:4[/tex], respectively.

Therefore, [tex]\displaystyle[NDC]=\frac{1}{4}[AMC]=\frac{1}{8}[ABC]=\frac{1}{8}\alpha[/tex].

We can use the same concept for triangle MEB. Triangle MEB is similar to triangle ANB, and the ratio of their sides is also [tex]1:2[/tex], since E is the midpoint of BN. Their areas are in the ratio [tex]1:2^2=1:4[/tex] and we have [tex]\displaystyle [MBE]=\frac{1}{4}[ANB]=\frac{1}{8}\alpha[/tex].

Thus,

[tex]\displaystyle \frac{[ABC]}{[BCDE]+[MNDE]}=\frac{\alpha}{\alpha-\frac{1}{4}\alpha-\frac{1}{8}\alpha-\frac{1}{8}\alpha}=\frac{\alpha}{0.5\alpha}=\frac{1}{\frac{1}{2}}=\boxed{2}[/tex]