Question

choose the point-slope form of the equation below that represents the line that passes through the points (-3,2) and (2,1)

Answer 1

So,

First, we'll find the slope.
$slope = \frac{rise}{run}$

We have to subtract 2 from 1 and -3 from 2.
1 - 2 = -1
2 - -3 = 5

So the slope is:
$\frac{-1}{5}$

Now, we have the following:
$y = \frac{-1}{5} x + b$

Now, we can solve for the y-intercept.

Use the ordered pair (2,1) to solve.
$1 = \frac{-1}{5}(2) + b$

Distribute.
$1 = \frac{-2}{5} + b$

Add 2/5 to both sides.
$1 \frac{2}{5} = b$

So the point-slope form of the line that passes through the points (-3,2) and (2,1) is:
$y = \frac{-1}{5} x + 1 \frac{2}{5}$