Answer
$ y=3$
The point is: $(3,7)$
Work Step by Step
We find the value of y that makes the two known lines a right angle:
$m_1 = \frac{-3-1}{-2-(-5) } = -4/3$
$m_2 = \frac{y+3}{8}$
Perpendicular lines have opposite reciprocal slopes, so:
$\frac{y+3}{8} = \frac{3}{4} \\ 4y+12=24 \\ 4y = 12 \\ y =3$
Using the properties of triangles, this means that the point is: $(3,7)$
