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3 years ago

I'm not sure what's the answer

Mathematics

1 answer:

kow [346]3 years ago

8 0

Answer:

m=17/40 $\frac{17}{40}$

Step-by-step explanation:

So you 5/7m - 1/7 = 9/56 $\frac{5}{7}m - \frac{1}{7} = \frac{9}{56}$

You Simplify both sides Then

well I Don´t know I hope this helped u, I tried ^^¨

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the equation of the line a is given as y = -3/4 x -2. Suppose the line a is parallel to line b and lime t is perpendicular to li

Orlov [11]

Answer:

equation 'b': y = -3/4x + 5

equation 't': y = 4/3x - 2

Step-by-step explanation:

parallel lines must have the same slope

the slope of perpendicular lines must be opposite and reciprocal

7 0

3 years ago

The amount of time the husband and the wife spend on house work is measured for 15 women and their 15 husbands. For the wives th

dolphi86 [110]

Answer:

The value of the test statistic is z = -0.877.

Step-by-step explanation:

Testing the difference in mean time spent on housework between husbands and wives.

At the null hypothesis, we test if there is no difference, that is, the subtraction of the means is 0:

$H_0: \mu_H - \mu_W = 0$

At the alternate hypothesis, we test if there is a difference, that is, the subtraction of the means is different from 0.

$H_1: \mu_H - \mu_W \neq 0$

The test statistic is:

$z = \frac{X - \mu}{s}$

In which X is the sample mean, $\mu$ is the value tested at the null hypothesis, and s is the standard error.

0 is tested at the null hypothesis:

This means that $\mu = 0$

For the wives the mean was 7 hours/week and for the husbands the mean was 4.5 hours/week. The standard deviation of the differences in time spent on house work was 2.85.

This means that $X = 4.5 - 7 = -2.5, s = 2.85$

What is the value of the test statistic for testing the difference in mean time spent on housework between husbands and wives?

$z = \frac{X - \mu}{s}$

$z = \frac{-2.5 - 0}{2.85}$

$z = -0.877$

The value of the test statistic is z = -0.877.

4 0

3 years ago

21 is what percent of 30?

ra1l [238]

$\frac{21}{30} *100=70$

(Divide then multiply by 100 and you get your answer)
- - Answer: 70%

5 0

3 years ago

The line for which equation has negative slope?

zhenek [66]

Answer:

Step-by-step explanation:

To have a negative slope, <em>m</em> has to be negative. Any negative slope would show up as a negative coefficient in front of <em>x</em>.

3 0

3 years ago

For which function is f(x) equal to f^1(x) ( answer choices in picture )

Sonja [21]

Answer:

C. $f(x)=\frac{x+1}{x-1}$

Step-by-step explanation:

Let's find the inverse of each of the given options.

Option A:

$f(x)=\frac{x+6}{x-6}\\y=\frac{x+6}{x-6}$

To find $f^{-1}(x)$ , replace 'x' with 'y' and 'y' with 'x'. This gives,

$x=\frac{y+6}{y-6}$

Rewrite in terms of 'y'. This gives,

$x(y-6)=y+6\\xy-6x=y+6\\xy-y=6x+6\\y=\frac{6x+6}{x-1}$

The given function $y=\frac{6x+6}{x-1}\ne y=\frac{x+6}{x-6}$

So, option A is incorrect.

Option B:

$f(x)=\frac{x+2}{x-2}\\y=\frac{x+2}{x-2}$

To find $f^{-1}(x)$ , replace 'x' with 'y' and 'y' with 'x'. This gives,

$x=\frac{y+2}{y-2}$

Rewrite in terms of 'y'. This gives,

$x(y-2)=y+2\\xy-2x=y+2\\xy-y=2x+2\\y=\frac{2x+2}{x-1}$

The given function $y=\frac{2x+2}{x-1}\ne y=\frac{x+2}{x-2}$

So, option B is incorrect.

Option C:

$f(x)=\frac{x+1}{x-1}\\y=\frac{x+1}{x-1}$

To find $f^{-1}(x)$ , replace 'x' with 'y' and 'y' with 'x'. This gives,

$x=\frac{y+1}{y-1}$

Rewrite in terms of 'y'. This gives,

$x(y-1)=y+1\\xy-x=y+1\\xy-y=x+1\\y=\frac{x+1}{x-1}$

The given function $y=\frac{x+1}{x-1}\ equals\ y=\frac{x+1}{x-1}$

So, option C is correct.

Option D:

$f(x)=\frac{x+5}{x-5}\\y=\frac{x+5}{x-5}$

To find $f^{-1}(x)$ , replace 'x' with 'y' and 'y' with 'x'. This gives,

$x=\frac{y+5}{y-5}$

Rewrite in terms of 'y'. This gives,

$x(y-5)=y+5\\xy-5x=y+5\\xy-y=5x+5\\y=\frac{5x+5}{x-1}$

The given function $y=\frac{5x+5}{x-1}\ne y=\frac{x+6}{x-6}$

So, option D is incorrect.

Therefore, only option C is correct.

7 0

3 years ago