Question

if x is the first, or smallest, of three consecutive integers, express the sum of the integer and the third integer as an algebraic expression containing the variable x.

Answer 1

Consecutive numbers differ by one. So, if $x$ is the first, the three numbers are

$x,\ x+1,\ x+2$

The sum of the first and third integer is

$x+(x+2)=2x+2$