Hello!
The formula for the slope is seen below.
[tex] \frac{ y_{2} - y_{1} }{ x_{2} x_{1} } [/tex]
The twos and ones represent either one of the y-values or x-values on the line. Any ordered pair can represent the ones or twos and the slope will be the same.
We will have (-3,1) be ([tex] x_{1} , y_{1}[/tex]) and (1,-2) be ([tex] x_{2} y_{2}[/tex]). We will plug these numbers into the equation.
[tex] \frac{-2-1}{1+3} = -\frac{3}{4} [/tex]
Therefore our slope is [tex]- \frac{3}{4} [/tex].
I hope this helps!