SOLUTION: x2-5x-14=0 solve in completing the square in quadratic equation

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Question 615350: x2-5x-14=0 solve in completing the square in quadratic equation
Found 2 solutions by nerdybill, unlockmath:
Answer by nerdybill(7384) About Me  (Show Source):
You can put this solution on YOUR website!
x%5E2-5x-14=0
x%5E2-5x=14
take 1/2 'b', square it and add to both sides:
x%5E2-5x%2B+25%2F4+=+14%2B25%2F4
+%28x-5%2F2%29%5E2+=+56%2F4+%2B+25%2F4
+%28x-5%2F2%29%5E2+=+81%2F4
+x-5%2F2+=+sqrt%2881%2F4%29
x = 5/2 +-9/2
.
x = {-4/2, 14/2}
or
x = {-2, 7}

Answer by unlockmath(1688) About Me  (Show Source):
You can put this solution on YOUR website!
Hello,
First, let's add 14 to both sides.
x2-5x=14
Add 25/4 to both sides:
x2-5x+25/4=20 1/4
Factor this to:
(x-5/2)^2=20 1/4
Now square root both sides:
x-5/2=+-9/2
Add 5/2 to get:
x=7
x=-2
Make sense?
RJ
www.math-unlock.com