Answer:
8 years
Step-by-step explanation:
Lets write an equation for Type A
The initial value is 5 ft and the slope 12 inches
We need to have the same units, so lets change 5 ft to inches
5 ft * 12 inches / ft = 60 inches
y = mx+b
y = 12 x + 60
Lets write an equation for Type B
The initial value is 3 ft and the slope 15 inches
We need to have the same units, so lets change 3 ft to inches
3 ft * 12 inches / ft = 36 inches
y = mx+b
y = 15 x + 36
We want to know when y is the same value. We can set the equations equal.
12x + 60 = 15x+36
Subtract 12 x from each side
12x-12x+60 = 15x-12x +36
60 =3x+36
Subtract 36 from each side
60-36 = 3x+36-36
24 = 3x
Divide each side by 3
24/3 = 3x/3
8 =x
It will take 8 years for the trees to be the same height
