Substitute x=4 and y=0 in every equation. If both sides of the equal sign are equal, (LS=RS, left side equals right side) then the graph intersects at (4,0).
The square root of x will be evaluated first before the addition of 5. Hence (-3)^2 = 9 and 9 +5 = 14, as per your teacher's answer, which is correct. The answer would not be -4.