Let line L1 be the graph of5x+8y=-9. Line l2 is perpendicular to line L1 and passes through the point (10,10).
If line L2 is the graph of the equation y=mx+b, then find m+b.
5x+8y= -9
8y = -5x-9
y= -5/8 x - 9/5 slope = m = -5/8
Perpindicular slope = 8/5
L2 y = 8/5 x + b
10 = 8/5 (10) + b
b = -6
L2 y = 8/5 x -6 m+ b = 8/5 - 6 = -22/5