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:

$m=\frac{y2-y1}{x2-x1}=\frac{48-30}{8-2}=\frac{18}{6}=3$

Using the point-slope equation:

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

Solve for y:

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