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

$-6x+(-13)x$, simplifies to $-19x$
the product of $-6$ and a number ... $\rightarrow$... $-6x$ ...which is increased by ... $\rightarrow -6x+...$ .... the product of $-13$ and a number$\quad\rightarrow -6x+(-13)x.$ This simplifies, first using the distributive property, $...=[ -6+(-13)]x$ ... then, adding same signed numbers, we keep the sign and add their absolute values: $=-(6+13)x$ $=-19x$