Question

Find the equation of a line that contains the points (8,2) and (−8,−8). Write the equation in slope-intercept form, using fractions when required.

Answer 1

Lets find the slope first.

Slope is change in y's by change in x's.

Change in y's = -8 -2 = -10

Change in x's = -8 -8 = -16

Slope = -10/-16 = 5/8

The slope intercept form is:

y = mx + b

Where

m is slope

b is y intercept

We now have:

`y=(5)/(8)x+b`

We can plug in any point and find b. Let's put (8,2), so :

`\begin{gathered} y=(5)/(8)x+b \\ 2=(5)/(8)(8)+b \\ 2=5+b \\ b=2-5 \\ b=-3 \end{gathered}`

Final equation:

`y=(5)/(8)x-3`