SOLUTION: Solve by completing the square. x^2 = 5x + 2 My answer that I got is 5+-SQRT33/2 Is that correct?

Algebra ->  Equations -> SOLUTION: Solve by completing the square. x^2 = 5x + 2 My answer that I got is 5+-SQRT33/2 Is that correct?      Log On


   

Question 84356: Solve by completing the square.
x^2 = 5x + 2

My answer that I got is 5+-SQRT33/2
Is that correct?
Found 2 solutions by funmath, tutorcecilia:
Answer by funmath(2933) About Me  (Show Source):
You can put this solution on YOUR website!
Solve by completing the square.
x^2 = 5x + 2
x%5E2-5x=-5x%2B5x%2B2
x%5E2-5x=2
x%5E2-5x%2B%285%2F2%29%5E2=2%2B%285%2F2%29%5E2
%28x-5%2F2%29%5E2=2%2B25%2F4
x-5%2F2%29%5E2=2%284%2F4%29%2B25%2F4
x-5%2F2%29%5E2=8%2F4%2B25%2F4
%28x-5%2F2%29%5E2=33%2F4
sqrt%28%28x-5%2F2%29%5E2%29=%2B-sqrt%2833%2F4%29
x-5%2F2=%2B-sqrt%2833%29%2F2
x=5%2F2%2B-sqrt%2833%29%2F2
x=%285%2B-sqrt%2833%29%29%2F2
I think your right, it's hard to tell for sure because you didn't put the whole numerator in parentheses.
Happy Calculating!!!

Answer by tutorcecilia(2152) About Me  (Show Source):
You can put this solution on YOUR website!
x^2 = 5x + 2 [re-write in the standard form: Ax+By=C]
.
x^2-5x = 5x-5x + 2 [isolate the constant to one side of the equation]
x^2 -5x= 2
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x^2 -5x +(5/2)^2= 2 +(5/2)^2 [divide the "B" term by (2) and raise it to the second power; also add it to the other side of the equation]
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x^2 -5x +(5/2)^2= 2 +(25/4) [simplify the rifht side of the equation as much as possible]
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x^2 -5x +(5/2)^2= 2 + 6.25 [I changed the fraction into a decimal]
.
x^2 -5x +(5/2)^2= 8.25
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(x-5/2)(x-5/2)= 8.25 [factor the left side only]
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(x-5/2)^2= 8.25 [simplify]
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%28sqrt%28%28x-5%2F2%29%5E2%29%29= %28sqrt%288.25%29%29 [take the square root of both sides]
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x-5/2=+-%28sqrt%288.25%29%29 [plus or minus the square root of 8.25]
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x-5/2 + 5/2 = +5/2 +-%28sqrt%288.25%29%29 [isolate the x-term]
x=5/2 + -%28+sqrt+%288.25%29%29
.