Chapter 1 - Introduction to Algebraic Expressions - 1.2 The Commutative, Associative, and Distributive Laws - 1.2 Exercise Set - Page 17: 71

$5x+5y+10$

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, $(x+y+2)5=x(5)+y(5)+2(5)=x\times5+y\times5+2\times5=5x+5y+10$.