A blue spruce grows an average of 6 inches per year. A hemlock grows an average of 4 inches per year. If a blue spruce is 4 feet tall and a hemlock is 6 feet tall, when would you expect the trees to be the same height?

Answer: it will take 12 years for both trees to be of the same height.

Step-by-step explanation:

Let x represent the number of years that it will take for the blue spruce and the hemlock to be the same height.

A blue spruce grows an average of 6 inches per year. If a blue spruce is 4 feet tall,

1 inch = 0.0833 feet

6 inches = 6 * 0.0833 = 0.4998 feet

it means that its height in x years would be

0.4998x + 4

A hemlock grows an average of 4 inches per year. If a hemlock is 6 feet tall.

4 inches = 4 * 0.0833 = 0.3332 feet

it means that its height in x years would be

0.3332x + 6

The number of years that it will take both trees to be of same height is

0.4998x + 4 = 0.3332x + 6

0.4998x - 0.3332x = 6 - 4

0.1666x = 2

x = 2/0.1666

x = 12