Write an equation to find the value of x so that each pair of polygons has the same perimeter. Then solve.
a. 3x + 18 = 4x + 10; 4
b. 3x + 18 = 4x + 10; 8
c. 3x + 18 = 4x + 10; 7
d. 3x + 18 = 2x + 5; –13
