The perimeter of a rectangular lawn is 24m. If the area of the lawn is 35m\(^2\), how wide is the lawn?
A
5cm
B
7m
C
12m
D
14m
Verified Correct Answer: B.
Step-by-Step Mathematical Solution
Perimeter. of a rectangle = 2(L + B) = 24
Area of a rectangle = L x B = 35
From above, L + B = 12
L = 12 - B
L x B = 35(given)
12 - B)B = 35
12B - B\(^2\) = 35
B\(^2\) - 12B + 35 = 0
B\(^2\) - 7B - 5B + 35 = 0
B(B - 7) - 5(B - 7) = 0
(B-5)(B -7) = 0
B = 5m OR 7m
Source: Myschool Past Questions Archive (Record #31461)