Answer:
30
Step-by-step explanation:
Perimeter of rectangle = 5y - 1 + 4y + 2 + 5y - 1 + 4y + 2
= 18y + 2
18y + 2 = 128
18y = 128 - 2
= 126
y = 126 ÷ 18
y = 7
Length of AD = 4y + 2
= 4(7) + 2
= 28 + 2
= 30