## Elementary and Intermediate Algebra: Concepts & Applications (6th Edition)

$3x+15$
The distributive law states that $a(b+c)=ab+ac$ (for real numbers $a$, $b$, and $c$). That is, the product of a number and a sum can be written as two products. Therefore, $3(x+5)=3(x)+3(5)=3x+15$.