The original height of the plant is 20 inches, and each week for 4 weeks its height increases by 2h inches, so at the end of 4 weeks its height would be:
20 + 4(2h) = 20 + 8h
Now for the next two weeks the plant grows in height by h inches each week, so we need to add a further 2h inches to the equation. Thus the expression that shows the height of the plant after 6 weeks is:
20 + 8h + 2h = 20 + 10h, therefor A is the correct answer
