## Introductory Algebra for College Students (7th Edition)

$12x-3x,$ simplifies to $9x$
"the product of three and a number" $\rightarrow 3x$ is subtracted from "the product of 12 and a number" $\rightarrow 12x$ So, 3x is subtracted from 12x:$\quad 12x-3x$ Combine like terms by combining the coefficients of the terms and keeping the same variable factor. $12x-3x=\qquad 9x$