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x^{2}+2x=\left(2x-1\right)\left(x+2\right)
Use the distributive property to multiply x+2 by x.
x^{2}+2x=2x^{2}+3x-2
Use the distributive property to multiply 2x-1 by x+2 and combine like terms.
x^{2}+2x-2x^{2}=3x-2
Subtract 2x^{2} from both sides.
-x^{2}+2x=3x-2
Combine x^{2} and -2x^{2} to get -x^{2}.
-x^{2}+2x-3x=-2
Subtract 3x from both sides.
-x^{2}-x=-2
Combine 2x and -3x to get -x.
-x^{2}-x+2=0
Add 2 to both sides.
x=\frac{-\left(-1\right)±\sqrt{1-4\left(-1\right)\times 2}}{2\left(-1\right)}
This equation is in standard form: ax^{2}+bx+c=0. Substitute -1 for a, -1 for b, and 2 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-\left(-1\right)±\sqrt{1+4\times 2}}{2\left(-1\right)}
Multiply -4 times -1.
x=\frac{-\left(-1\right)±\sqrt{1+8}}{2\left(-1\right)}
Multiply 4 times 2.
x=\frac{-\left(-1\right)±\sqrt{9}}{2\left(-1\right)}
Add 1 to 8.
x=\frac{-\left(-1\right)±3}{2\left(-1\right)}
Take the square root of 9.
x=\frac{1±3}{2\left(-1\right)}
The opposite of -1 is 1.
x=\frac{1±3}{-2}
Multiply 2 times -1.
x=\frac{4}{-2}
Now solve the equation x=\frac{1±3}{-2} when ± is plus. Add 1 to 3.
x=-2
Divide 4 by -2.
x=-\frac{2}{-2}
Now solve the equation x=\frac{1±3}{-2} when ± is minus. Subtract 3 from 1.
x=1
Divide -2 by -2.
x=-2 x=1
The equation is now solved.
x^{2}+2x=\left(2x-1\right)\left(x+2\right)
Use the distributive property to multiply x+2 by x.
x^{2}+2x=2x^{2}+3x-2
Use the distributive property to multiply 2x-1 by x+2 and combine like terms.
x^{2}+2x-2x^{2}=3x-2
Subtract 2x^{2} from both sides.
-x^{2}+2x=3x-2
Combine x^{2} and -2x^{2} to get -x^{2}.
-x^{2}+2x-3x=-2
Subtract 3x from both sides.
-x^{2}-x=-2
Combine 2x and -3x to get -x.
\frac{-x^{2}-x}{-1}=-\frac{2}{-1}
Divide both sides by -1.
x^{2}+\left(-\frac{1}{-1}\right)x=-\frac{2}{-1}
Dividing by -1 undoes the multiplication by -1.
x^{2}+x=-\frac{2}{-1}
Divide -1 by -1.
x^{2}+x=2
Divide -2 by -1.
x^{2}+x+\left(\frac{1}{2}\right)^{2}=2+\left(\frac{1}{2}\right)^{2}
Divide 1, the coefficient of the x term, by 2 to get \frac{1}{2}. Then add the square of \frac{1}{2} to both sides of the equation. This step makes the left hand side of the equation a perfect square.
x^{2}+x+\frac{1}{4}=2+\frac{1}{4}
Square \frac{1}{2} by squaring both the numerator and the denominator of the fraction.
x^{2}+x+\frac{1}{4}=\frac{9}{4}
Add 2 to \frac{1}{4}.
\left(x+\frac{1}{2}\right)^{2}=\frac{9}{4}
Factor x^{2}+x+\frac{1}{4}. 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+\frac{1}{2}\right)^{2}}=\sqrt{\frac{9}{4}}
Take the square root of both sides of the equation.
x+\frac{1}{2}=\frac{3}{2} x+\frac{1}{2}=-\frac{3}{2}
Simplify.
x=1 x=-2
Subtract \frac{1}{2} from both sides of the equation.