Let line l1 be the graph of 5x+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 .
+128407 5x + 8y = -9
In the form Ax + By = C
The slope is -A / B
So....the slope of L1 is -5/8
And L2 is a perpendicular line to L1.....so.....it has a negative reciprocal slope = 8/5
So.....the equation of L2 is
y = (8/5) x - 10) + 10
y = (8/5)x - 16 + 10
y = (8/5)x - 6
So
m + b = (8/5) - 6 = (8/5) - 30/5 = - 22/5
