College Algebra CLEP Prep Practice Exam

Find the inverse of the function y = 5x.

1. x = 5y

2. x = 1/5y

3. y = 1/5x

4. y = 5/x

The correct answer is: x = 1/5y

An inverse function is a function that undoes the action of the original function. In this case, the function y = 5x multiplies the input value by 5 to get the output value. To undo this action and find the inverse function, we need to divide the output value by 5 to get the input value. Therefore, the inverse function will be x = 1/5y, as for every input value (y) the original function multiplied by 5, the inverse function will divide by 5 to get the original input value. Options A, C, and D do not correctly represent the inverse function of y = 5x. Option A has the variables in the incorrect order, option C has the variables incorrectly inverted, and option D adds an additional step by dividing by the input value.