Start with the slope formula, shown below.
m = y₂ - y₁ / x₂ - x₁
We take the second y minus the first y over the second x minus the first x.
So we have m = -8 - 4 / 9 - 1 or -12/8.
Notice that -12/8 can be reduced to -3/2.
So the slope of this line is -3/2.
The variable that's used to represent slope is m.
So here, we would say that m = -3/2.
