SOLUTION: 2x^2-3x=5 completing the square

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Question 331423: 2x^2-3x=5 completing the square
Found 2 solutions by galactus, ankor@dixie-net.com:
Answer by galactus(183) About Me  (Show Source):
You can put this solution on YOUR website!
When completing the square, use the formula:
a%2A%28x%2Bb%2F%282a%29%29%5E2%2Bc-b%5E2%2F%284a%29
Simply plug in a=2, b=-3, c=-5
And get:
2%28x-3%2F4%29%5E2-49%2F8

Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
2x^2-3x=5 completing the square
;
We need the coefficient of x^2, to be 1, divide each term by 2, and you have
x^2 - 3%2F2x = 5%2F2
:
x^2 - 3%2F2x + ____ = 5%2F2
:
%283%2F4%29%5E2 will complete the square. add to both sides
x^2 - 3%2F2x + 9%2F16 = 5%2F2 + 9%2F16
:
x^2 - 3%2F2x + 9%2F16 = 40%2F16 + 9%2F16
:
x^2 - 3%2F2x + 9%2F16 = 49%2F16
:
(x - 3%2F4)^2 = 49%2F16
:
Find the square root of both sides
x - 3%2F4 = +/-sqrt%2849%2F16%29
:
x = 3%2F4 +/-sqrt%2849%2F16%29
a perfect square
x = 3%2F4 +/-7%2F4
Two solutions
x = 3%2F4 + 7%2F4
x = 10%2F4
x = 21%2F2
and
x = 3%2F4 - 7%2F4
x = -4%2F4
x = -1
:
:
Check solution in original equation using x=2.5
2(2.5^2) -3(2.5) = 5
2(6.25) - 7.5 = 5
12.5 - 7.5 = 5; confirms our solution,
:
You can check solution for x=-1