How do you find the inverse of f(x)=(3-8x)/(x+5)?

Question

How do you find the inverse of f(x)=(3-8x)/(x+5)?

Answer 1

Is this Calculus?

Cause if it is, I'm dropping out of school.

Answer 2

y=f(x) = (3-8x)/(x+5)

Multiply each side by x+5

y(x+5) = 3-8x

Distribute y

yx +5y = 3-8x

Put all values with an x on one side and put everything else on the other side.

yx +8x = 3-5y

Factor out the x

x(y+8) = 3-5y

Solve for x:

x= (3-5y)/(y+8)

Switch x and y:

y= (3-5x)/(x+8) = f^-1 (x) (doesnt exist for x=-8)

Answer 3

y=(3-8x)/(x+5) so yx+5y = 3-8x and x(-y-8)= 5y-3 so x=(5y-3)/(-y-8)

interchanging x and y the inverse function is y= (5x-3)/(-x-8)