SOLUTION: Find the value of " x " such that the slope of the line containing (x,5) and (3,-1) is 4

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Question 49435: Find the value of " x " such that the slope of the line containing (x,5) and (3,-1) is 4
Answer by Born2TeachMath(20) About Me  (Show Source):
You can put this solution on YOUR website!
This problem uses the formula for the slope backwards to find a missing value.
Start the problem with the equation for slope:
m+=+%28y1+-+y2%29%2F%28x1+-+x2%29
Plug in what we know:
x1 = x,
y1 = 5
x2 = 3
y2 = -1
m = 4
So 4+=+%285+-+-1%29%2F%28x+-+3%29
Simplify: 4+=+6%2F%28x+-+3%29 since 5 - -1 = 6
Solve:
4*(x - 3) = 6 (Cross multiply)
4x - 12 = 6 (Distribute the 4)
4x = 18 (Add 12 to both sides)
x = 18/4 (Divide both sides by 4)
x = 9/2 (Reduce the fraction to lowest terms)