Question

Margaret and Donovan are twins. They

Answer 1

The rate of a linear function is its slope.

The slope is defined via the "rise over run" ratio, i.e.

$m = \dfrac{\Delta y}{\Delta x} = \dfrac{y_2-y_1}{x_2-x_1}$

If you pick any two columns from the table and perform this operation (for example the first two), you have

$m = \dfrac{y_2-y_1}{x_2-x_1} = \dfrac{105-101}{6-5}=4$

On the other hand, given an equation like $y=mx+b$, the slope is the coefficient m. So, the rate of $y=5a+84$ is 5.

This means that Margaret grows 4cm per year, while Donovan grows 5cm per year, and therefore he grows faster.