Perpendicular lines have opposite reciprocal slopes
the original line: y = 5/2x + 5
The perpendicular line: y = -2/5x + b
To find b, we have to plug (-10, 5) into x and y for our perpendicular line
5 = -2/5(-10) + b
Simplify the right side
5 = 4 + b
Subtract 4 from both sides
1 = b
The final answer = y = -2/5x + 1
