Solve for x
x=-4
x=1
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3\times 2+3\left(x+2\right)\left(-\frac{1}{3}\right)=\left(x+2\right)x
Variable x cannot be equal to -2 since division by zero is not defined. Multiply both sides of the equation by 3\left(x+2\right), the least common multiple of x+2,3.
6+3\left(x+2\right)\left(-\frac{1}{3}\right)=\left(x+2\right)x
Multiply 3 and 2 to get 6.
6-\left(x+2\right)=\left(x+2\right)x
Multiply 3 and -\frac{1}{3} to get -1.
6-x-2=\left(x+2\right)x
To find the opposite of x+2, find the opposite of each term.
4-x=\left(x+2\right)x
Subtract 2 from 6 to get 4.
4-x=x^{2}+2x
Use the distributive property to multiply x+2 by x.
4-x-x^{2}=2x
Subtract x^{2} from both sides.
4-x-x^{2}-2x=0
Subtract 2x from both sides.
4-3x-x^{2}=0
Combine -x and -2x to get -3x.
-x^{2}-3x+4=0
Rearrange the polynomial to put it in standard form. Place the terms in order from highest to lowest power.
a+b=-3 ab=-4=-4
To solve the equation, factor the left hand side by grouping. First, left hand side needs to be rewritten as -x^{2}+ax+bx+4. To find a and b, set up a system to be solved.
1,-4 2,-2
Since ab is negative, a and b have the opposite signs. Since a+b is negative, the negative number has greater absolute value than the positive. List all such integer pairs that give product -4.
1-4=-3 2-2=0
Calculate the sum for each pair.
a=1 b=-4
The solution is the pair that gives sum -3.
\left(-x^{2}+x\right)+\left(-4x+4\right)
Rewrite -x^{2}-3x+4 as \left(-x^{2}+x\right)+\left(-4x+4\right).
x\left(-x+1\right)+4\left(-x+1\right)
Factor out x in the first and 4 in the second group.
\left(-x+1\right)\left(x+4\right)
Factor out common term -x+1 by using distributive property.
x=1 x=-4
To find equation solutions, solve -x+1=0 and x+4=0.
3\times 2+3\left(x+2\right)\left(-\frac{1}{3}\right)=\left(x+2\right)x
Variable x cannot be equal to -2 since division by zero is not defined. Multiply both sides of the equation by 3\left(x+2\right), the least common multiple of x+2,3.
6+3\left(x+2\right)\left(-\frac{1}{3}\right)=\left(x+2\right)x
Multiply 3 and 2 to get 6.
6-\left(x+2\right)=\left(x+2\right)x
Multiply 3 and -\frac{1}{3} to get -1.
6-x-2=\left(x+2\right)x
To find the opposite of x+2, find the opposite of each term.
4-x=\left(x+2\right)x
Subtract 2 from 6 to get 4.
4-x=x^{2}+2x
Use the distributive property to multiply x+2 by x.
4-x-x^{2}=2x
Subtract x^{2} from both sides.
4-x-x^{2}-2x=0
Subtract 2x from both sides.
4-3x-x^{2}=0
Combine -x and -2x to get -3x.
-x^{2}-3x+4=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(-3\right)±\sqrt{\left(-3\right)^{2}-4\left(-1\right)\times 4}}{2\left(-1\right)}
This equation is in standard form: ax^{2}+bx+c=0. Substitute -1 for a, -3 for b, and 4 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-\left(-3\right)±\sqrt{9-4\left(-1\right)\times 4}}{2\left(-1\right)}
Square -3.
x=\frac{-\left(-3\right)±\sqrt{9+4\times 4}}{2\left(-1\right)}
Multiply -4 times -1.
x=\frac{-\left(-3\right)±\sqrt{9+16}}{2\left(-1\right)}
Multiply 4 times 4.
x=\frac{-\left(-3\right)±\sqrt{25}}{2\left(-1\right)}
Add 9 to 16.
x=\frac{-\left(-3\right)±5}{2\left(-1\right)}
Take the square root of 25.
x=\frac{3±5}{2\left(-1\right)}
The opposite of -3 is 3.
x=\frac{3±5}{-2}
Multiply 2 times -1.
x=\frac{8}{-2}
Now solve the equation x=\frac{3±5}{-2} when ± is plus. Add 3 to 5.
x=-4
Divide 8 by -2.
x=-\frac{2}{-2}
Now solve the equation x=\frac{3±5}{-2} when ± is minus. Subtract 5 from 3.
x=1
Divide -2 by -2.
x=-4 x=1
The equation is now solved.
3\times 2+3\left(x+2\right)\left(-\frac{1}{3}\right)=\left(x+2\right)x
Variable x cannot be equal to -2 since division by zero is not defined. Multiply both sides of the equation by 3\left(x+2\right), the least common multiple of x+2,3.
6+3\left(x+2\right)\left(-\frac{1}{3}\right)=\left(x+2\right)x
Multiply 3 and 2 to get 6.
6-\left(x+2\right)=\left(x+2\right)x
Multiply 3 and -\frac{1}{3} to get -1.
6-x-2=\left(x+2\right)x
To find the opposite of x+2, find the opposite of each term.
4-x=\left(x+2\right)x
Subtract 2 from 6 to get 4.
4-x=x^{2}+2x
Use the distributive property to multiply x+2 by x.
4-x-x^{2}=2x
Subtract x^{2} from both sides.
4-x-x^{2}-2x=0
Subtract 2x from both sides.
4-3x-x^{2}=0
Combine -x and -2x to get -3x.
-3x-x^{2}=-4
Subtract 4 from both sides. Anything subtracted from zero gives its negation.
-x^{2}-3x=-4
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.
\frac{-x^{2}-3x}{-1}=-\frac{4}{-1}
Divide both sides by -1.
x^{2}+\left(-\frac{3}{-1}\right)x=-\frac{4}{-1}
Dividing by -1 undoes the multiplication by -1.
x^{2}+3x=-\frac{4}{-1}
Divide -3 by -1.
x^{2}+3x=4
Divide -4 by -1.
x^{2}+3x+\left(\frac{3}{2}\right)^{2}=4+\left(\frac{3}{2}\right)^{2}
Divide 3, the coefficient of the x term, by 2 to get \frac{3}{2}. Then add the square of \frac{3}{2} to both sides of the equation. This step makes the left hand side of the equation a perfect square.
x^{2}+3x+\frac{9}{4}=4+\frac{9}{4}
Square \frac{3}{2} by squaring both the numerator and the denominator of the fraction.
x^{2}+3x+\frac{9}{4}=\frac{25}{4}
Add 4 to \frac{9}{4}.
\left(x+\frac{3}{2}\right)^{2}=\frac{25}{4}
Factor x^{2}+3x+\frac{9}{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{3}{2}\right)^{2}}=\sqrt{\frac{25}{4}}
Take the square root of both sides of the equation.
x+\frac{3}{2}=\frac{5}{2} x+\frac{3}{2}=-\frac{5}{2}
Simplify.
x=1 x=-4
Subtract \frac{3}{2} from both sides of the equation.
Examples
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{ x } ^ { 2 } - 4 x - 5 = 0
Trigonometry
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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
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