(1,-3) is a solution.
Work Step by Step
We are given that $y=\sqrt x-4$. In order to see whether each ordered pair is a solution of the given equation, we can plug in the ordered pair to the equation. For (1,-3): $\sqrt 1-4=1-4=-3$ So, (1,-3) is a solution. For (8,6): $\sqrt 8-4=2-4=-2\ne6$ So, (8,6) is not a solution.