find the equation in slope-intercept form for the line that contains the given point and that is parallel to the given line.

M(-5,2); -3x+8y=24

I have no idea what the M means in front of (-5,2), so will ignore it.

The slope of the given line can be seen by rewriting the equation in y = mx+b form:
y = (3/8)x + 3
The slope is therefore 3/8.
A line passing through (-5,2) with that slope can be written
y -2 = (3/8)[x -(-5)] = 3/8(x+5)
or
y = (3/8)x + 31/8