Solve for x
x=-18
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\left(2x+12\right)\times 0+\left(2x-12\right)\times 6+x^{2}-36=0
Variable x cannot be equal to any of the values -6,6 since division by zero is not defined. Multiply both sides of the equation by 2\left(x-6\right)\left(x+6\right)^{2}, the least common multiple of x^{2}-36,\left(x+6\right)^{2},2x+12.
0+\left(2x-12\right)\times 6+x^{2}-36=0
Anything times zero gives zero.
0+12x-72+x^{2}-36=0
Use the distributive property to multiply 2x-12 by 6.
-72+12x+x^{2}-36=0
Subtract 72 from 0 to get -72.
-108+12x+x^{2}=0
Subtract 36 from -72 to get -108.
x^{2}+12x-108=0
Rearrange the polynomial to put it in standard form. Place the terms in order from highest to lowest power.
a+b=12 ab=-108
To solve the equation, factor x^{2}+12x-108 using formula x^{2}+\left(a+b\right)x+ab=\left(x+a\right)\left(x+b\right). To find a and b, set up a system to be solved.
-1,108 -2,54 -3,36 -4,27 -6,18 -9,12
Since ab is negative, a and b have the opposite signs. Since a+b is positive, the positive number has greater absolute value than the negative. List all such integer pairs that give product -108.
-1+108=107 -2+54=52 -3+36=33 -4+27=23 -6+18=12 -9+12=3
Calculate the sum for each pair.
a=-6 b=18
The solution is the pair that gives sum 12.
\left(x-6\right)\left(x+18\right)
Rewrite factored expression \left(x+a\right)\left(x+b\right) using the obtained values.
x=6 x=-18
To find equation solutions, solve x-6=0 and x+18=0.
x=-18
Variable x cannot be equal to 6.
\left(2x+12\right)\times 0+\left(2x-12\right)\times 6+x^{2}-36=0
Variable x cannot be equal to any of the values -6,6 since division by zero is not defined. Multiply both sides of the equation by 2\left(x-6\right)\left(x+6\right)^{2}, the least common multiple of x^{2}-36,\left(x+6\right)^{2},2x+12.
0+\left(2x-12\right)\times 6+x^{2}-36=0
Anything times zero gives zero.
0+12x-72+x^{2}-36=0
Use the distributive property to multiply 2x-12 by 6.
-72+12x+x^{2}-36=0
Subtract 72 from 0 to get -72.
-108+12x+x^{2}=0
Subtract 36 from -72 to get -108.
x^{2}+12x-108=0
Rearrange the polynomial to put it in standard form. Place the terms in order from highest to lowest power.
a+b=12 ab=1\left(-108\right)=-108
To solve the equation, factor the left hand side by grouping. First, left hand side needs to be rewritten as x^{2}+ax+bx-108. To find a and b, set up a system to be solved.
-1,108 -2,54 -3,36 -4,27 -6,18 -9,12
Since ab is negative, a and b have the opposite signs. Since a+b is positive, the positive number has greater absolute value than the negative. List all such integer pairs that give product -108.
-1+108=107 -2+54=52 -3+36=33 -4+27=23 -6+18=12 -9+12=3
Calculate the sum for each pair.
a=-6 b=18
The solution is the pair that gives sum 12.
\left(x^{2}-6x\right)+\left(18x-108\right)
Rewrite x^{2}+12x-108 as \left(x^{2}-6x\right)+\left(18x-108\right).
x\left(x-6\right)+18\left(x-6\right)
Factor out x in the first and 18 in the second group.
\left(x-6\right)\left(x+18\right)
Factor out common term x-6 by using distributive property.
x=6 x=-18
To find equation solutions, solve x-6=0 and x+18=0.
x=-18
Variable x cannot be equal to 6.
\left(2x+12\right)\times 0+\left(2x-12\right)\times 6+x^{2}-36=0
Variable x cannot be equal to any of the values -6,6 since division by zero is not defined. Multiply both sides of the equation by 2\left(x-6\right)\left(x+6\right)^{2}, the least common multiple of x^{2}-36,\left(x+6\right)^{2},2x+12.
0+\left(2x-12\right)\times 6+x^{2}-36=0
Anything times zero gives zero.
0+12x-72+x^{2}-36=0
Use the distributive property to multiply 2x-12 by 6.
-72+12x+x^{2}-36=0
Subtract 72 from 0 to get -72.
-108+12x+x^{2}=0
Subtract 36 from -72 to get -108.
x^{2}+12x-108=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{-12±\sqrt{12^{2}-4\left(-108\right)}}{2}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 1 for a, 12 for b, and -108 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-12±\sqrt{144-4\left(-108\right)}}{2}
Square 12.
x=\frac{-12±\sqrt{144+432}}{2}
Multiply -4 times -108.
x=\frac{-12±\sqrt{576}}{2}
Add 144 to 432.
x=\frac{-12±24}{2}
Take the square root of 576.
x=\frac{12}{2}
Now solve the equation x=\frac{-12±24}{2} when ± is plus. Add -12 to 24.
x=6
Divide 12 by 2.
x=-\frac{36}{2}
Now solve the equation x=\frac{-12±24}{2} when ± is minus. Subtract 24 from -12.
x=-18
Divide -36 by 2.
x=6 x=-18
The equation is now solved.
x=-18
Variable x cannot be equal to 6.
\left(2x+12\right)\times 0+\left(2x-12\right)\times 6+x^{2}-36=0
Variable x cannot be equal to any of the values -6,6 since division by zero is not defined. Multiply both sides of the equation by 2\left(x-6\right)\left(x+6\right)^{2}, the least common multiple of x^{2}-36,\left(x+6\right)^{2},2x+12.
0+\left(2x-12\right)\times 6+x^{2}-36=0
Anything times zero gives zero.
0+12x-72+x^{2}-36=0
Use the distributive property to multiply 2x-12 by 6.
-72+12x+x^{2}-36=0
Subtract 72 from 0 to get -72.
-108+12x+x^{2}=0
Subtract 36 from -72 to get -108.
12x+x^{2}=108
Add 108 to both sides. Anything plus zero gives itself.
x^{2}+12x=108
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.
x^{2}+12x+6^{2}=108+6^{2}
Divide 12, the coefficient of the x term, by 2 to get 6. Then add the square of 6 to both sides of the equation. This step makes the left hand side of the equation a perfect square.
x^{2}+12x+36=108+36
Square 6.
x^{2}+12x+36=144
Add 108 to 36.
\left(x+6\right)^{2}=144
Factor x^{2}+12x+36. 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+6\right)^{2}}=\sqrt{144}
Take the square root of both sides of the equation.
x+6=12 x+6=-12
Simplify.
x=6 x=-18
Subtract 6 from both sides of the equation.
x=-18
Variable x cannot be equal to 6.
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