### Home > APCALC > Chapter 8 > Lesson 8.3.1 > Problem8-107

8-107.

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

1. $3$

1. $0$

1. $-9$

1. $-12$

1. $-18$

Start by writing an equation with only one variable. Let $f(x) = xy$. Then use $y = 3x − 12$ 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 $x$.