SOLUTION: Solve using complete the square. 2x^2+13x+20

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Question 1116329: Solve using complete the square.
2x^2+13x+20
Found 2 solutions by ankor@dixie-net.com, stanbon:
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
Solve using complete the square.
2x^2+13x+20 = 0
:
2x^2 + 13x = -20
we want the coefficient of x^2 to be 1, divide equation by 2
x^2 + 6.5x = -10
complete the square: %286.5%2F2%29%5E2+=+10.5625, add to both sides
x^2 + 6.5x + 10.5625 = -10 + 10.6525
(x + 3.25)^2 = .5625
Find the square root of both sides
x + 3.25 = +/-sqrt%28.5625%29
two solutions
x = -3.25 +sqrt%28.5625%29
x = -3.25 + .75
x = -2.5
and
x = -3.25 -sqrt%28.5625%29
x = -3.25 - .75
x = -4

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Solve using complete the square.
2x^2+13x-20 = 0
-----
x^2 + (13/2)x = -10
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x^2 + (13/2)x + (13/4)^2 = -10 + (13/4)^2
-----
(x+(13/4))^2 = (-160 + 169)/16
----
(x+(13/4))^2 = 9/16
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Cheers,
Stan H.
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