Question 56066
If f(x) = 5x - 7, what is f^-1(x)?

f(x)=5x-7 can also be written as:
y=5x-7,  now interchange x and y, and solve for y:
x=5y-7
+7 +7
x+7=5y
y=x/5+7/5

so f^-1(x)=x/5+7/5