SOLUTION: A line passing through (-4,4) and (x,-8) is perpendicular to a line with slope 5/12, Find the value of x

Algebra ->  Linear-equations -> SOLUTION: A line passing through (-4,4) and (x,-8) is perpendicular to a line with slope 5/12, Find the value of x      Log On


   

Question 243523: A line passing through (-4,4) and (x,-8) is perpendicular to a line with slope 5/12, Find the value of x
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
Remember that the perpendicular slope is the negative reciprocal of the original slope. So flip 5%2F12 to get 12%2F5 and change the sign to get -12%2F5. So the perpendicular slope is m=-12%2F5


m=%28y%5B2%5D-y%5B1%5D%29%2F%28x%5B2%5D-x%5B1%5D%29 Start with the slope formula.


-12%2F5=%28-8-4%29%2F%28x--4%29 Plug in m=-12%2F5, y%5B2%5D=-8, y%5B1%5D=4, x%5B2%5D=x, and x%5B1%5D=-4


-12%2F5=%28-8-4%29%2F%28x%2B4%29 Rewrite x--4 as x%2B4


-12%2F5=%28-12%29%2F%28x%2B4%29 Combine like terms.


-12%28x%2B4%29=5%28-12%29 Cross multiply.


-12x-12%284%29=5%28-12%29 Distribute


-12x-48=-60 Multiply


-12x=-60%2B48 Add 48 to both sides.


-12x=-12 Combine like terms on the right side.


x=%28-12%29%2F%28-12%29 Divide both sides by -12 to isolate x.


x=1 Reduce.


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Answer:

So the solution is x=1