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0.5x^{2}-x+0.5=0
All equations of the form ax^{2}+bx+c=0 can be solved using the quadratic formula: \frac{-b±\sqrt{b^{2}-4ac}}{2a}. The quadratic formula gives two solutions, one when ± is addition and one when it is subtraction.
x=\frac{-\left(-1\right)±\sqrt{1-4\times 0.5\times 0.5}}{2\times 0.5}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 0.5 for a, -1 for b, and 0.5 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-\left(-1\right)±\sqrt{1-2\times 0.5}}{2\times 0.5}
Multiply -4 times 0.5.
x=\frac{-\left(-1\right)±\sqrt{1-1}}{2\times 0.5}
Multiply -2 times 0.5.
x=\frac{-\left(-1\right)±\sqrt{0}}{2\times 0.5}
Add 1 to -1.
x=-\frac{-1}{2\times 0.5}
Take the square root of 0.
x=\frac{1}{2\times 0.5}
The opposite of -1 is 1.
x=\frac{1}{1}
Multiply 2 times 0.5.
0.5x^{2}-x+0.5=0
Quadratic equations such as this one can be solved by completing the square. In order to complete the square, the equation must first be in the form x^{2}+bx=c.
0.5x^{2}-x+0.5-0.5=-0.5
Subtract 0.5 from both sides of the equation.
0.5x^{2}-x=-0.5
Subtracting 0.5 from itself leaves 0.
\frac{0.5x^{2}-x}{0.5}=-\frac{0.5}{0.5}
Multiply both sides by 2.
x^{2}+\left(-\frac{1}{0.5}\right)x=-\frac{0.5}{0.5}
Dividing by 0.5 undoes the multiplication by 0.5.
x^{2}-2x=-\frac{0.5}{0.5}
Divide -1 by 0.5 by multiplying -1 by the reciprocal of 0.5.
x^{2}-2x=-1
Divide -0.5 by 0.5 by multiplying -0.5 by the reciprocal of 0.5.
x^{2}-2x+1=-1+1
Divide -2, the coefficient of the x term, by 2 to get -1. Then add the square of -1 to both sides of the equation. This step makes the left hand side of the equation a perfect square.
x^{2}-2x+1=0
Add -1 to 1.
\left(x-1\right)^{2}=0
Factor x^{2}-2x+1. In general, when x^{2}+bx+c is a perfect square, it can always be factored as \left(x+\frac{b}{2}\right)^{2}.
\sqrt{\left(x-1\right)^{2}}=\sqrt{0}
Take the square root of both sides of the equation.
x-1=0 x-1=0
Simplify.
x=1 x=1
Add 1 to both sides of the equation.
x=1
The equation is now solved. Solutions are the same.