Answer:
length = 10 cm
width = 4 cm
Step-by-step explanation:
width = w
length = 2w + 2
area = 40 ft²
A = lw
40 = (w)(2w + 2)
40 = 2w² + 2w
2w² + 2w - 40 = 40 - 40
____________
2w² + 2w - 40 = 0
w² + w - 20 = 0
(w+5) (w-4) =0
w+5 - 5 = 0 - 5
_______
w = -5 - there's
no negative measurement/s
w - 4 + 4 = 0 + 4
_______
w = 4
w = 4 = width
length = 2w + 2 = 2(4) + 2 = 10ft
check:
A = lw
A = 40
40 = 10 × 4
40 = 40✓
