SOLUTION: What equation represents a line perpendicular to a line that passes through (3,-6) and (-5,4)?

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Question 1080375: What equation represents a line perpendicular to a line that passes through (3,-6) and (-5,4)?
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
What equation represents a line perpendicular to a line that passes through (3,-6) and (-5,4)?
:
Find the slope of the original equation line
m = %284+-%28-6%29%29%2F%28-5-3%29 = %284+%2B+6%29%2F%28-8%29 = 10%2F%28-8%29 = -5%2F4
Find the equation using the point/slope form y - y1 = m(x-x1)
y -(-6) = -5%2F4(x - 3)
y + 6 = -5%2F4x + -15%2F4%29
y = -5%2F4x + 15%2F4%29 - 6
y = -5%2F4x + 15%2F4%29 - 24%2F4
y = -5%2F4x - 9%2F4%29 is the equation
Pick a point between x=-5 and x=3, us x=-1, find y: y = -1
:
Find the slope of a perpendicular line (m2)
-5%2F4 * m2 = -1
m2 = -1 *-4%2F5
m2 = 4%2F5 is the slope of the perpendicular line
we want it to pass thru the point -1,-1, find the y intercept, b
4%2F5(-1) + b = -1
-4%2F5 + b = -1
b = -1 + 4%2F5
b = -1%2F5
the perpendicular line equation
y = 4%2F5x - 1%2F5
:
looks like this

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