Let line 1 be the graph of 5x+8y=-9. Line 2 is perpendicular to line 1 and passes through the point (10,-12). If line 2 is the graph of the equation y=mx+b, then find. m+b
5x+8y=-9 is the same as y = - 5/8 x - 9/8 slope , m = -5/8 perpindicular slope = - 1/m = 8/5
so you new line becomes
y = 8/5 x + b sub in the given point to find b
-12 = 8/5 (10) + b
b = - 28
y = 8/5 x - 28 You can finish !