The perimeter of the rectangle ABCD:
P = 2AD + 2AB
We have AD = 4z and AB = 5z + 2 and perimeter = 220 units. Substitute:
2(4z) + 2(5z + 2) = 220 use distributive property
8z + (2)(5z) + (2)(2) = 220
8z + 10z + 4 = 220 subtract 4 from both sides
18z = 216 divide both sides by 18
z = 12 units
Substitute to AD:
AD = 4(12) = 48
Answer: AD = 48 units.
