## anonymous one year ago I'm confused on something can anyone help? for medal?

1. anonymous

Which function below is the inverse of f(x) = The quantity of three x plus five, over seven.?

2. anonymous

f−1(x) = The quantity of seven x minus five, over three f−1(x) = The quantity of seven x plus five, over three −f−1(x) = Seven over the quantity of three x plus five f−1(x) = Seven over the quantity of five minus three x

3. Mehek14

$$\dfrac{3x+5}{7}$$ ?

4. anonymous

yes :)

5. anonymous

@DJthereal here's something i need help on

6. anonymous

@LynFran

7. anonymous

option First. want solution?

8. anonymous

LOL, i'm lost? what do you mean whats the solution A. f−1(x) = The quantity of seven x minus five, over three B. f−1(x) = The quantity of seven x plus five, over three C. −f−1(x) = Seven over the quantity of three x plus five D .f−1(x) = Seven over the quantity of five minus three x

9. anonymous

A is correct! solution means how to get it!

10. anonymous

whats tha equation??

11. anonymous

nvm i see

12. anonymous

A sounds good. but y A?

13. anonymous

i think its B or A

14. anonymous

@DJthereal same but i think someone needs to show me how to find the answer. i have a test coming up soon. thats why i'd ask why it's A.

15. anonymous

1 sec...i had a problem similar to this but i can't find my old notebook

16. anonymous

$f(x)=\frac{ 7x-5 }{ 3}\\ switch \ x\ and\ f(x)\\ x=\frac{ 7f(x)-5 }{ 3 }\\solving \ for\ f(x)\\f(x)=\frac{ 3x+5 }{ 7}\\putting\ f(x)= inverse\ f(x)\\ \therefore \ inverse\ f(x)= \frac{ 3x+5 }{ 7 }$

17. anonymous

thats A??

18. anonymous

wait which one did @eninone jus solve??

19. anonymous

20. anonymous

oh! no ! a plus sign missed! hey! @nerlineg check out my solution, Option A is Correct.

21. anonymous

$given\ f(x) = \frac{ 3x+5 }{ 7}\\ switch\ x\ and \ f(x)\\ i.e. x \ becomes\ f(x) \ and \ f(x) \ becomes\ x\\ x=\frac{ 3f(x)+5 }{ 7},\ solve\ for\ f(x)\\7x=3f(x)+5\\7x-5=3f(x)\\f(x)=\frac{ 7x-5 }{ 3 }\\replace\ f(x) \ by\ inverse\ f(x)\\i.e.,\ inverse\ f(x)=\frac{ 7x-5 }{ 3 }\\clearly\ option\ A \ is\ Correct!$

22. ybarrap

Yes, @eninone has the correct solution.

23. anonymous

yeah, my teacher did a typo, but yup you are right thanks ! i actually do understand it now. with everyone's help on here ! @eninone @ DJthereal

24. anonymous

@DJthereal

25. anonymous

You should read 'How to Sove it' by George Polya. https://en.wikipedia.org/wiki/George_P%C3%B3lya http://www-history.mcs.st-andrews.ac.uk/Biographies/Polya.html