Margaret and donovan are twins. they
have each kept track of their heights
every year since they were 5.
margaret made a table to track her
height.
age, a 5 | 6 | 7
height, h (cm) 101 105 109
|
8
113
| 9
| 117
| 10
| 121
donovan wrote an equation to track his height: h = 5a + 84
which statement correctly compares the twins' rates of growth?

The rate of a linear function is its slope.

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

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

On the other hand, given an equation like , the slope is the coefficient m. So, the rate of is 5.

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

correct answer:

b.(19,-2)