Answer:
H = (20 + 9h) in
Step-by-step explanation:
Let
H = height of the plant after 6 weeks
h0 = initial height
x = increment after 6 weeks
H = h0 + x
The plant grows 2h inches each week for 4 weeks
2h * 4 = 8h
h inches for each 2 weeks after that,
This means,
x = 8h + h = 9h
Then,
H = (20 + 9h) in