Question

If f(x)=15x-7 then f^-1(x)​

Answer 1

Hi!

So, we need to find the inverse of the function f(x) = 15x - 7.

To start, we must turn the f(x) into a y.

y = 15x - 7.

Now, we swap all the x variables for the y variables, and swap all the y variables for the x variables!

x = 15y - 7.

Now, we simply must work on isolating y. Assuming you know how to isolate a variable, we must do the steps below -

x = 15y - 7.

Add 7 on both sides.

x + 7 = 15y - 7 + 7.

We cannot add x and 7, as they are not like terms. So, they will remain like that, while the 7 on the right side of the equation is eliminated.

x + 7 = 15y.

Now we are going to divide both sides by 15, thus leaving y by itself.

= 15y / 15.

Since we cannot divide the left side of the equation by 15, it will remain as such. With the y variable completely isolated, our final inverse function will be:

= .

Hopefully, this helps! =)