SOLUTION: Please!! I need help to solve by completing the square: 2x^2 -9x + 4 = 0 and 4 x^2 + x = 0 Thank you so much for your help!!

Algebra ->  Rational-functions -> SOLUTION: Please!! I need help to solve by completing the square: 2x^2 -9x + 4 = 0 and 4 x^2 + x = 0 Thank you so much for your help!!      Log On


   

Question 532007: Please!! I need help to solve by completing the square:
2x^2 -9x + 4 = 0
and
4 x^2 + x = 0
Thank you so much for your help!!
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Please!! I need help to solve by completing the square:
2x^2 -9x + 4 = 0
x^2 -(9/2)x = -2
x^2 -(9/2)x + (9/4)^2 = -2 + (9/4)^2
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(x-(9/4))^2 = -32/16 + 81/16
---
(x-(9/4))^2 = 49/16
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x-(9/4) = +-7/4
===
x = +(7/4)+(9/4) or x = -(7/4)+(9/4)
----
x = 4 or x = 1/2
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and
4 x^2 + x = 0
x^2 + (1/4)x = 0
x^2 + (1/4)x + (1/8)^2 = (1/8)^2
(x+(1/8))^2 = (1/8)^2
(x + (1/8)) = +-(1/8)
x = (1/8)-(1/8) or x = -(1/8)-(1/8)
x = 0 or x = -1/4
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Cheers,
Stan H.
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