### Home > CALC > Chapter 8 > Lesson 8.3.1 > Problem 8-106

8-106.

**Multiple Choice: **If *y* = 3*x* − 12, then the minimum product for *xy *is:

3

0

−9

−12

−18

Before using Calculus, write an equation with only one variable. Let *f*(*x*) = *xy*. Then use *y* = 3*x* − 12 to solve write *f*(*x*) in terms of *x* only.

Optimize. Remember that you are looking for the minimum product, not the minimum value of *x*.