anonymous one year ago I'll give a medal again please help!! Juliana has created the function f(x) = the quantity of 3x plus 2, divided by 4 to represent the cost of texting on her current plan, where x represents the number of texts. Juliana discovers that, using the inverse function to solve for x = 24, she can predict how many texts she can use for $24. Explain to Juliana how to accomplish this, using complete sentences. • This Question is Closed 1. anonymous The equation that Juliana created is $f(x)=\frac{ 3x+2 }{ 4 }$. Plug in 24 for x. She wants to be able to know the amount of texts she can send with$24. Solve the equation by dividing.

2. anonymous

so it would 3x+2= 4 right?

3. anonymous

So I just realized that your problem says find the inverse function.. Okay, to find the inverse of the function, you need to set f(x) into y and exchange the positions of y and x in the equation then solve for y. $f(x)=\frac{ 3x+2 }{ 4 }$ would turn into $y=\frac{ 3x+2 }{ 4 }$ $x=\frac{ 3y+2 }{ 4 }$ From here, isolate the y value.

4. anonymous

By isolating the value, you need to put 3y on one side of the equation.

5. anonymous

so 3y+2 over 4

6. anonymous

Work from $x=\frac{ 3y+2 }{ 4 }$ Isolate the y by multiplying both sides of the equation with 4. By multiplying both sides of the equation by 4, it will cancel out dividing the 4 on the y side.

7. anonymous

After you've multiplied both sides by 4, the equation is now 4x = 3y + 2. You have to subtract 2 from both sides of the equation again to isolate y.

8. anonymous

do i subtract the 2 from the y or x

9. anonymous

You subtract them from both.

10. anonymous

You have to get y by itself. After you've subtract 2 from both sides, 3y is still on one side of the equation. How would you get 3y to turn into y?

11. anonymous

by multiply the 3y right

12. anonymous

No, you divide the 3y to get 3. Now, the equation is $y = \frac{ 4x+2 }{ 3y }$ That's the inverse function of the original function that Juliana created. Now, plug in 24 for x.

13. anonymous

"$x=\frac{4x-2 }{ 3 }$" sorry my mistake

14. anonymous

Now what do i do?

15. anonymous

Do you want to this in private chat?

16. anonymous

Plug in 24 for x. That's the last calculation

17. anonymous

so 24x-2 over 3

18. anonymous

$x=\frac{4(24)-2 }{ 3 }$

19. anonymous

ok i check that and divide it i got a decimal , is that fine?

20. anonymous

You possibly can't have a decimal as the answer. Julianna can't send a half of a text. You need to calculate the numerator first. Then, divide the numerator by the denominator.

21. anonymous

i did

22. anonymous

But there's still a decimal

23. anonymous

Well, try to do the first part of the actual equation. What is 4 * 24?

24. anonymous

ok, that is 96

25. anonymous

Subtract 2 from 96.

26. anonymous

-94

27. anonymous

96 - 2 is 94. Divide by 3. Round your answer so that it doesn't have any decimals.

28. anonymous

31

29. anonymous

Correct

30. anonymous

Thank you so much!!

31. anonymous