How do you find the slope of (-2,7) , (-3,3)?

If $\left(- 2 , 7\right)$ and $\left(- 3 , 3\right)$ are points, then the slope is $4$.
Slope is $\frac{y - {y}_{1}}{x - {x}_{1}}$. In this case, $y = 7$ and ${y}_{1} = 3$, so $y - {y}_{1} = 4$. $x = - 2$, and ${x}_{1} = - 3$, so $x - {x}_{1} = 1$. Thus, the slope is $\frac{4}{1}$, or just $4$.