Let line L_1 be the graph of 5x + 8y = -9. Line L_2 is perpendicular to line L_1 and passes through the point (10,-10). If line L_2 is the graph of the equation y=mx +b, then find m+b.

Guest Jun 27, 2021

#1**0 **

Rearranging line L_1 into intercept form,

y = -5/8x - 9/8

If line L_2 is perpendicular, it would have slope 8/5,

y = 8/5x + b

Plugging in (10, -10),

-10 = 16 + b

b = -26

Therefore m+b is 8/5 + (-26) = **-24.4** or **-24 2/5**

Awesomeguy Jun 27, 2021