Let's say that x is the width.
AREA OF A RECTANGLE
A =?
l = (x + 5) cm
w = (x) cm
A = l • w
A = (x + 5) cm • (x) cm
A = (x² + 5x) cm²
PERIMETER OF A RECTANGLE
P = ?
l = (x + 5) cm
w = (x) cm
P = 2l + 2w
P = 2 (x + 5) + 2 (x)
P = 2x + 10 + 2x
P = (4x + 10) cm
I hope it works.