Write equation that describes the function

Looking for patterns, we can easily see that we subtract 2 for every 2 inputs. Therefore, the slope is change in y/change in x=(0-(-2))/(1-3)=2/-2=-1. Therefore, our equation is at y=-x+b since from y=mx+b we have m as the slope, which is -1 in this case. Plugging (5, -4) in, we get 5=4+b. Subtracting 4 from both sides, we get b=1, making our equation y=-x+1 since y and x should stay as variables