Solve for x
x=\sqrt{7}+4\approx 6.645751311
x=4-\sqrt{7}\approx 1.354248689
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\left(x+1\right)\times 3x+\left(-2-2x\right)x-\left(x-1\right)\times 9=0
Variable x cannot be equal to any of the values -1,1 since division by zero is not defined. Multiply both sides of the equation by 2\left(x-1\right)\left(x+1\right), the least common multiple of 2x-2,1-x,2x+2.
\left(3x+3\right)x+\left(-2-2x\right)x-\left(x-1\right)\times 9=0
Use the distributive property to multiply x+1 by 3.
3x^{2}+3x+\left(-2-2x\right)x-\left(x-1\right)\times 9=0
Use the distributive property to multiply 3x+3 by x.
3x^{2}+3x-2x-2x^{2}-\left(x-1\right)\times 9=0
Use the distributive property to multiply -2-2x by x.
3x^{2}+x-2x^{2}-\left(x-1\right)\times 9=0
Combine 3x and -2x to get x.
x^{2}+x-\left(x-1\right)\times 9=0
Combine 3x^{2} and -2x^{2} to get x^{2}.
x^{2}+x-\left(9x-9\right)=0
Use the distributive property to multiply x-1 by 9.
x^{2}+x-9x+9=0
To find the opposite of 9x-9, find the opposite of each term.
x^{2}-8x+9=0
Combine x and -9x to get -8x.
x=\frac{-\left(-8\right)±\sqrt{\left(-8\right)^{2}-4\times 9}}{2}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 1 for a, -8 for b, and 9 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-\left(-8\right)±\sqrt{64-4\times 9}}{2}
Square -8.
x=\frac{-\left(-8\right)±\sqrt{64-36}}{2}
Multiply -4 times 9.
x=\frac{-\left(-8\right)±\sqrt{28}}{2}
Add 64 to -36.
x=\frac{-\left(-8\right)±2\sqrt{7}}{2}
Take the square root of 28.
x=\frac{8±2\sqrt{7}}{2}
The opposite of -8 is 8.
x=\frac{2\sqrt{7}+8}{2}
Now solve the equation x=\frac{8±2\sqrt{7}}{2} when ± is plus. Add 8 to 2\sqrt{7}.
x=\sqrt{7}+4
Divide 8+2\sqrt{7} by 2.
x=\frac{8-2\sqrt{7}}{2}
Now solve the equation x=\frac{8±2\sqrt{7}}{2} when ± is minus. Subtract 2\sqrt{7} from 8.
x=4-\sqrt{7}
Divide 8-2\sqrt{7} by 2.
x=\sqrt{7}+4 x=4-\sqrt{7}
The equation is now solved.
\left(x+1\right)\times 3x+\left(-2-2x\right)x-\left(x-1\right)\times 9=0
Variable x cannot be equal to any of the values -1,1 since division by zero is not defined. Multiply both sides of the equation by 2\left(x-1\right)\left(x+1\right), the least common multiple of 2x-2,1-x,2x+2.
\left(3x+3\right)x+\left(-2-2x\right)x-\left(x-1\right)\times 9=0
Use the distributive property to multiply x+1 by 3.
3x^{2}+3x+\left(-2-2x\right)x-\left(x-1\right)\times 9=0
Use the distributive property to multiply 3x+3 by x.
3x^{2}+3x-2x-2x^{2}-\left(x-1\right)\times 9=0
Use the distributive property to multiply -2-2x by x.
3x^{2}+x-2x^{2}-\left(x-1\right)\times 9=0
Combine 3x and -2x to get x.
x^{2}+x-\left(x-1\right)\times 9=0
Combine 3x^{2} and -2x^{2} to get x^{2}.
x^{2}+x-\left(9x-9\right)=0
Use the distributive property to multiply x-1 by 9.
x^{2}+x-9x+9=0
To find the opposite of 9x-9, find the opposite of each term.
x^{2}-8x+9=0
Combine x and -9x to get -8x.
x^{2}-8x=-9
Subtract 9 from both sides. Anything subtracted from zero gives its negation.
x^{2}-8x+\left(-4\right)^{2}=-9+\left(-4\right)^{2}
Divide -8, the coefficient of the x term, by 2 to get -4. Then add the square of -4 to both sides of the equation. This step makes the left hand side of the equation a perfect square.
x^{2}-8x+16=-9+16
Square -4.
x^{2}-8x+16=7
Add -9 to 16.
\left(x-4\right)^{2}=7
Factor x^{2}-8x+16. 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-4\right)^{2}}=\sqrt{7}
Take the square root of both sides of the equation.
x-4=\sqrt{7} x-4=-\sqrt{7}
Simplify.
x=\sqrt{7}+4 x=4-\sqrt{7}
Add 4 to both sides of the equation.
Examples
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{ x } ^ { 2 } - 4 x - 5 = 0
Trigonometry
4 \sin \theta \cos \theta = 2 \sin \theta
Linear equation
y = 3x + 4
Arithmetic
699 * 533
Matrix
\left[ \begin{array} { l l } { 2 } & { 3 } \\ { 5 } & { 4 } \end{array} \right] \left[ \begin{array} { l l l } { 2 } & { 0 } & { 3 } \\ { -1 } & { 1 } & { 5 } \end{array} \right]
Simultaneous equation
\left. \begin{cases} { 8x+2y = 46 } \\ { 7x+3y = 47 } \end{cases} \right.
Differentiation
\frac { d } { d x } \frac { ( 3 x ^ { 2 } - 2 ) } { ( x - 5 ) }
Integration
\int _ { 0 } ^ { 1 } x e ^ { - x ^ { 2 } } d x
Limits
\lim _{x \rightarrow-3} \frac{x^{2}-9}{x^{2}+2 x-3}