Solve for x
x=-4
x=-1
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x^{2}+5x+6=2
Use the distributive property to multiply x+2 by x+3 and combine like terms.
x^{2}+5x+6-2=0
Subtract 2 from both sides.
x^{2}+5x+4=0
Subtract 2 from 6 to get 4.
x=\frac{-5±\sqrt{5^{2}-4\times 4}}{2}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 1 for a, 5 for b, and 4 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-5±\sqrt{25-4\times 4}}{2}
Square 5.
x=\frac{-5±\sqrt{25-16}}{2}
Multiply -4 times 4.
x=\frac{-5±\sqrt{9}}{2}
Add 25 to -16.
x=\frac{-5±3}{2}
Take the square root of 9.
x=-\frac{2}{2}
Now solve the equation x=\frac{-5±3}{2} when ± is plus. Add -5 to 3.
x=-1
Divide -2 by 2.
x=-\frac{8}{2}
Now solve the equation x=\frac{-5±3}{2} when ± is minus. Subtract 3 from -5.
x=-4
Divide -8 by 2.
x=-1 x=-4
The equation is now solved.
x^{2}+5x+6=2
Use the distributive property to multiply x+2 by x+3 and combine like terms.
x^{2}+5x=2-6
Subtract 6 from both sides.
x^{2}+5x=-4
Subtract 6 from 2 to get -4.
x^{2}+5x+\left(\frac{5}{2}\right)^{2}=-4+\left(\frac{5}{2}\right)^{2}
Divide 5, the coefficient of the x term, by 2 to get \frac{5}{2}. Then add the square of \frac{5}{2} to both sides of the equation. This step makes the left hand side of the equation a perfect square.
x^{2}+5x+\frac{25}{4}=-4+\frac{25}{4}
Square \frac{5}{2} by squaring both the numerator and the denominator of the fraction.
x^{2}+5x+\frac{25}{4}=\frac{9}{4}
Add -4 to \frac{25}{4}.
\left(x+\frac{5}{2}\right)^{2}=\frac{9}{4}
Factor x^{2}+5x+\frac{25}{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{5}{2}\right)^{2}}=\sqrt{\frac{9}{4}}
Take the square root of both sides of the equation.
x+\frac{5}{2}=\frac{3}{2} x+\frac{5}{2}=-\frac{3}{2}
Simplify.
x=-1 x=-4
Subtract \frac{5}{2} from both sides of the equation.
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Limits
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