## Clongoria2 one year ago Inverse function question. Help please! Explain if possible!

1. Clongoria2

Which function below is the inverse of f(x) = 2x + 3/ 5

2. Clongoria2

A. f^-1(x) = 5x + 3/2 B. f^-1(x) = 5x - 3/2 C. f^-1(x) = 5/2x + 3 D. f^-1(x) = 5/ 3 -2x

3. anonymous

Hello! Is it $f(x)=\frac{ 2x+3 }{ 5 }$ or $f(x)=2x+ \frac{ 3}{ 5 }$?

4. Clongoria2

Its the first one. Im having trouble understanding what to do after switching the x and y variables

5. anonymous

So you already switched x and y like this? $x=\frac{ 2y+3 }{ 5 }$

6. Clongoria2

Yes I have

7. anonymous

All right! So now multiply 5 on both sides.

8. anonymous

What would you get?

9. Clongoria2

$5x = 2y + 3$

10. anonymous

Make the equation look like the slope-intercept form: $$y=mx+b$$.

11. anonymous

Do you know how?

12. Clongoria2

Do you mean $2y = 5x + 3$

13. Clongoria2

?

14. anonymous

Yes, but it should be $$2y = 5x - 3$$. :) Now divide both sides by 2, and that's it.

15. Clongoria2

$5x - 3 / 2 = y$

16. anonymous

$y= \frac{ 5x-3 }{ 2 }$ or $y=\frac{ 5x }{ 2 }-\frac{ 3 }{ 2 }$

17. Clongoria2

The first one. Sorry.

18. anonymous

Oh, you can write it either way I put it, but it is not $$y=5x-\frac{ 3 }{ 2 }$$.

19. Clongoria2

I know i meant to do $y = \frac{ 5x - 3 }{ 2}$

20. Clongoria2

Thank you so much!

21. anonymous

You're welcome! :)