Question

A rectangular banner has a length that is two feet shorter than twice its height, ℎ. If the expression ℎ(2ℎ−2) represents the area of the banner, what is the height of the banner whose area is 60

Answer 1

h = 6

Explanation:

Given he area of the banner expressed as;

A = ℎ(2ℎ−2)

h is the height of the banner

A is the area = 60

Substitute

60 = ℎ(2ℎ−2)

60 = 2h² - 2h

30 = h² - h

h²-h-30 = 0

Factorize;

h²-6h+5h-30 = 0

h(h-6)+5(h-6) = 0

(h-6)(h+5) = 0

h - 6 = 0 and h+5 = 0

h = 6 and -5

Since the height cannot be negative;

h = 6

Hence he height of the banner is 6