Question

Sandra bought a 4-inch tall plant from the nursery. The plant is growing at a constant rate. A month later, Sandra measured the plant to be 10 inches tall. Which equation represents the height (y ) of Sandra’s plant over time where x represents the number of months?

Answer 1

If the plant is growing at a constant rate, it means that it will grow the same every month.

When realizing that after a month, it increased 6 inches, it means the plant is growing 6 inches every month. We can create an equation of the following:

y = 4 + 6x

This means, that the height of the plant can be found by multiplying the number of months the plant has grown by 6 inches. We have to add the 4 to everything because that is the original height of the plant before she bought it, for which we need to include in the equation.