Find slope of line A:
Move into slope-intercept form y = mx+b
<span>5x + 8y = -9
8y = -5x - 9
y = (-5/8)x - 9/8
The slope of line A is -5/8.
If </span><span>Line B is perpendicular to line A, then
slope Line B = negative reciprocal of slope Line A</span>
<span>slope Line B = 8/5
So like B has the equation
y = (8/5)x + b
If it passes through (10,10), we know that when x = 10, y = 10. Use those values to solve for b:
</span>
<span>y = (8/5)x + b
10 = (8/5)·10 + b</span>
<span>10 = (8)·2 + b
10 = 16 + b
b = -6
So line B has equation </span>
<span>y = (8/5)x - 6
m = 8/5 and b = -6
so
m + b = 8/5 - 6 = 8/5 - 30/5 = -22/5
So m+b = -22/5 or -4.4 in decimal form
</span>
the answer have to be would be (-3, 1)
the difference from 240 to 120 is 50%
