If the line of best fit is \(y = -2x - 2\), then the predicted \(y\)-value when \(x = 1\) is \(-4\).
A residual is calculated by subtracting the predicted \(y\)-value from the actual \(y\)-value.
So, if you have the actual \(y\)-value for \(x = 1\), the residual will be that actual value minus \(-4\). This tells you how far the actual point is from the predicted point on the line.