AC is the same length as DE + EB
DE would be the same as EB, so we need to solve for those first:
6x+2 = x+17
Subtract 1 x from each side:
5x+2 = 17
Subtract 2 from each side:
5x = 15
Divide both sides by 5:
x = 15/5
x = 3
Noe we have a value for X, replace x with 3 in each equation and then add them together:
6x+2 = 6(3) +2 = 18+2 = 20
x+17 = 3 + 17 = 20
20 +20 = 40
AC = 40