All categories

3 years ago

Which expressions are equivalent to –9 (2/3x+1)? Check all that apply.

Mathematics

1 answer:

Degger [83]3 years ago

4 0

Answer:

-18/3x - 9

Step-by-step explanation:

-9(2/3x + 1)

Expand.

-18/3x + -9

You might be interested in

Solve for q. -5(3-q) +4=5q-11

soldier1979 [14.2K]

Perform the indicated multiplication first: -15 + 5q + 4 = 5q - 11

Note that 5q appears on both sides of this equation. Cancelling, we get :

-11 = -11. This is always true. Thus, -5(3-q) +4=5q-11 is true for all q.

4 0

3 years ago

B. The school prom committee sold presale tickets for

Ivan

Answer:

218 students purchased tickets at the dance.

Step-by-step explanation:

Let,

x be the number of presale tickets

y be the number of tickets sold at the dance

According to given statement;

x+y=334 Eqn 1

18x+24y=7320 Eqn 2

Multiplying Eqn 1 by 18

18(x+y=334)

18x+18y=6012 Eqn 3

Subtracting Eqn 3 from Eqn 2

(18x+24y)-(18x+18y)=7320-6012

18x+24y-18x-18y=1308

6y=1308

$\frac{6y}{6}=\frac{1308}{6}\\y=218$

Therefore,

218 students purchased tickets at the dance.

5 0

3 years ago

Please help this is timed

agasfer [191]

Answer: y= -2 (x+1)

Step-by-step explanation:

this would be the “inverse” of the original equation making them cross at exactly 1 point

7 0

3 years ago

10. Polygon WXYZ has vertices W(-1.5, 1.5),

vovikov84 [41]

Answer:

See explanation

Step-by-step explanation:

Polygon WXYZ has vertices W(-1.5, 1.5), X(6, 1.5), Y(6, -4.5), and Z(-1.5, -4.5).

Find the slopes of all sides:

$WX:\ \dfrac{1.5-1.5}{6-(-1.5)}=\dfrac{0}{7.5}=0$ - horizontal line

$XY:\ \dfrac{-4.5-1.5}{6-6}=\dfrac{-6}{0}$ - slope undefined, so the line is vertical

$YZ:\ \dfrac{-4.5-(-4.5)}{-1.5-6}=\dfrac{0}{-7.5}=0$ - horizontal line

$ZW:\ \dfrac{1.5-(-4.5)}{-1.5-(-1.5)}=\dfrac{6}{0}$ - slope undefined, so the line is vertical

Vertical and horizontal lines are perpendicular, so all angles W, X, Y and Z are right angles. Hence, quadrilateral WXYZ is a rectangle

6 0

4 years ago

A recent study examined hearing loss data for 1981 U.S. teenagers. In this sample, 369 were found to have some level of hearing

ruslelena [56]

Answer:

There is no enough evidence to support the claim that the proportion of US teens that have some level of hearing loss differs from 20%.

P-value=0.12

Step-by-step explanation:

We have to perform a test of hypothesis on the proportion.

The claim is that the proportion of US teens that have some level of hearing loss differs from 20%.

Then, the null and alternative hypothesis are:

$H_0: \pi=0.20\\\\H_a:\pi\neq0.20$

The significance level is assumed to be 0.05.

The sample, of size n=1981, has 369 positive cases. Then, the proportion is:

$p=X/n=369/1981=0.186$

The standard error of the proportion is:

$\sigma_p=\sqrt{\dfrac{\pi(1-\pi)}{n}}=\sqrt{\dfrac{0.2*0.8}{1981}}=\sqrt{ 0.000081 }= 0.009$

Now, we can calculate the statistic z:

$z=\dfrac{p-\pi+0.5/n}{\sigma_p}=\dfrac{0.186-0.20+0.5/1981}{0.009}=\dfrac{-0.014}{0.009}=-1.556$

The P-value for this two-tailed test is:

$P-value=2*P(z$

The P-value is below the significance level, so the effect is not significant. The null hypothesis failed to be rejected.

There is no enough evidence to support the claim that the proportion of US teens that have some level of hearing loss differs from 20%.

7 0

3 years ago