Answer:
Step-by-step explanation:
let y represent number of years...
9 ft tall = (12 * 9) = 108 inches
10 ft tall = (12 * 10) = 120 inches
Type A : 9 ft (or 108 inches) and grows 6 inches per year..
108 + 6y
Type B : 10 ft (or 120 inches) and grows 3 inches per yr
120 + 3y
how many years will it take them to be the same height...so when will they be equal....so set them equal and solve for y
108 + 6y = 120 + 3y
6y - 3y = 120 - 108
3y = 112
y = 112/3
y = 37 1/3 years....or 37 years and 4 months <====
check...
108 + 6(37 1/3) = 120 + 3(37 1/3)
108 + 6(112/3) = 120 + 3(112/3)
108 + 672/3 = 120 + 336/3
672/3 - 336/3 = 120 - 108
336/3 = 112
112 = 112 (correct)