Chapter 1, Equations and Inequalities - 1.3 Solve Linear Equations - 1.3 Exercises - Skill Practice - Page 22: 53

$x=2$ Side 1: $2x+2=6$ Side 2: $2x+2=6$ Side 3: $3x-3=3$

First, we add up all 3 sides as follows: Perimeter $=(2x+2)+(2x+2)+(3x-3)$ $=7x+1$ Then we set $7x+1$ equal to $15$ and simplify: $7x+1=15$ $7x=14$ $x=2$ Finally, we plug $x=2$ into the expressions for each of the sides to determine their length: Side 1: $2x+2 = (2\times2)+2 = 4+2 = 6$ Side 2: $2x+2 = (2\times2)+2 = 4+2 = 6$ Side 3: $3x-3 = (3\times2)-3 = 6-3 = 3$