Question

(a) Find a linear equation that represents the height of a boy versus his age.

Answer 1

Let:

`\begin{gathered} (x1,y1)=(2,30) \\ (x2,y2)=(8,48) \end{gathered}`

The slope m of the line is:

`m=(y2-y1)/(x2-x1)=(48-30)/(8-2)=(18)/(6)=3`

Using the point-slope equation:

`\begin{gathered} y-y1=m(x-x1) \\ y-30=3(x-2) \end{gathered}`

Solve for y:

`\begin{gathered} y-30=3x-6 \\ y=3x+24 \\ \end{gathered}`