Find f-1(x) if f(x)= 3/4 - 9/7x

Question

Find f-1(x) if f(x)= 3/4 - 9/7x

Answer 1

To find the inverse f^-1(x), switch x and y and solve for y:

f(x) = 3/4 - 9/7x

y = 3/4 - 9/7x

x = 3/4 - 9/7y

x - 3/4 = -9/7y

-7/9 (x - 3/4) = y

-7/9x - 7/12 = y

f^-1(x) = -7/9x - 7/12