SOLUTION: Solve the quadratic equation x2 - x = 30 by completing the square

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Question 465533: Solve the quadratic equation x2 - x = 30 by completing the square
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
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Solve the quadratic equation x^2 - x = 30
:
x^2 - x + ___ = 30
Find the term that completes the square: half the coefficient of x, squared: (1/2)^2 = 1/4
Add to both sides
x^2 - x + 1%2F4= 30 + 1%2F4
x^2 - x + 1%2F4= 120%2F4 + 1%2F4
x^2 - x + 1%2F4= 121%2F4
Which is:
(x - 1%2F2)^2 = 121%2F4
Find the square root of both sides
x - 1%2F2 = +/- sqrt%28121%2F4%29
x - 1%2F2 = +/- 11%2F2
Two solutions
x = 1%2F2 + 11%2F2
x = 12%2F2
x = +6
and
x = 1%2F2 - 11%2F2
x = -10%2F2
x = -5