Solve for x
x=-\frac{4}{7}\approx -0.571428571
x=1
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\left(x-3\right)\times 6=\left(x-3\right)\left(x+2\right)\times 7+\left(x+2\right)\times 10
Variable x cannot be equal to any of the values -2,3 since division by zero is not defined. Multiply both sides of the equation by \left(x-3\right)\left(x+2\right), the least common multiple of x+2,x-3.
6x-18=\left(x-3\right)\left(x+2\right)\times 7+\left(x+2\right)\times 10
Use the distributive property to multiply x-3 by 6.
6x-18=\left(x^{2}-x-6\right)\times 7+\left(x+2\right)\times 10
Use the distributive property to multiply x-3 by x+2 and combine like terms.
6x-18=7x^{2}-7x-42+\left(x+2\right)\times 10
Use the distributive property to multiply x^{2}-x-6 by 7.
6x-18=7x^{2}-7x-42+10x+20
Use the distributive property to multiply x+2 by 10.
6x-18=7x^{2}+3x-42+20
Combine -7x and 10x to get 3x.
6x-18=7x^{2}+3x-22
Add -42 and 20 to get -22.
6x-18-7x^{2}=3x-22
Subtract 7x^{2} from both sides.
6x-18-7x^{2}-3x=-22
Subtract 3x from both sides.
3x-18-7x^{2}=-22
Combine 6x and -3x to get 3x.
3x-18-7x^{2}+22=0
Add 22 to both sides.
3x+4-7x^{2}=0
Add -18 and 22 to get 4.
-7x^{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{-3±\sqrt{3^{2}-4\left(-7\right)\times 4}}{2\left(-7\right)}
This equation is in standard form: ax^{2}+bx+c=0. Substitute -7 for a, 3 for b, and 4 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-3±\sqrt{9-4\left(-7\right)\times 4}}{2\left(-7\right)}
Square 3.
x=\frac{-3±\sqrt{9+28\times 4}}{2\left(-7\right)}
Multiply -4 times -7.
x=\frac{-3±\sqrt{9+112}}{2\left(-7\right)}
Multiply 28 times 4.
x=\frac{-3±\sqrt{121}}{2\left(-7\right)}
Add 9 to 112.
x=\frac{-3±11}{2\left(-7\right)}
Take the square root of 121.
x=\frac{-3±11}{-14}
Multiply 2 times -7.
x=\frac{8}{-14}
Now solve the equation x=\frac{-3±11}{-14} when ± is plus. Add -3 to 11.
x=-\frac{4}{7}
Reduce the fraction \frac{8}{-14} to lowest terms by extracting and canceling out 2.
x=-\frac{14}{-14}
Now solve the equation x=\frac{-3±11}{-14} when ± is minus. Subtract 11 from -3.
x=1
Divide -14 by -14.
x=-\frac{4}{7} x=1
The equation is now solved.
\left(x-3\right)\times 6=\left(x-3\right)\left(x+2\right)\times 7+\left(x+2\right)\times 10
Variable x cannot be equal to any of the values -2,3 since division by zero is not defined. Multiply both sides of the equation by \left(x-3\right)\left(x+2\right), the least common multiple of x+2,x-3.
6x-18=\left(x-3\right)\left(x+2\right)\times 7+\left(x+2\right)\times 10
Use the distributive property to multiply x-3 by 6.
6x-18=\left(x^{2}-x-6\right)\times 7+\left(x+2\right)\times 10
Use the distributive property to multiply x-3 by x+2 and combine like terms.
6x-18=7x^{2}-7x-42+\left(x+2\right)\times 10
Use the distributive property to multiply x^{2}-x-6 by 7.
6x-18=7x^{2}-7x-42+10x+20
Use the distributive property to multiply x+2 by 10.
6x-18=7x^{2}+3x-42+20
Combine -7x and 10x to get 3x.
6x-18=7x^{2}+3x-22
Add -42 and 20 to get -22.
6x-18-7x^{2}=3x-22
Subtract 7x^{2} from both sides.
6x-18-7x^{2}-3x=-22
Subtract 3x from both sides.
3x-18-7x^{2}=-22
Combine 6x and -3x to get 3x.
3x-7x^{2}=-22+18
Add 18 to both sides.
3x-7x^{2}=-4
Add -22 and 18 to get -4.
-7x^{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{-7x^{2}+3x}{-7}=-\frac{4}{-7}
Divide both sides by -7.
x^{2}+\frac{3}{-7}x=-\frac{4}{-7}
Dividing by -7 undoes the multiplication by -7.
x^{2}-\frac{3}{7}x=-\frac{4}{-7}
Divide 3 by -7.
x^{2}-\frac{3}{7}x=\frac{4}{7}
Divide -4 by -7.
x^{2}-\frac{3}{7}x+\left(-\frac{3}{14}\right)^{2}=\frac{4}{7}+\left(-\frac{3}{14}\right)^{2}
Divide -\frac{3}{7}, the coefficient of the x term, by 2 to get -\frac{3}{14}. Then add the square of -\frac{3}{14} to both sides of the equation. This step makes the left hand side of the equation a perfect square.
x^{2}-\frac{3}{7}x+\frac{9}{196}=\frac{4}{7}+\frac{9}{196}
Square -\frac{3}{14} by squaring both the numerator and the denominator of the fraction.
x^{2}-\frac{3}{7}x+\frac{9}{196}=\frac{121}{196}
Add \frac{4}{7} to \frac{9}{196} by finding a common denominator and adding the numerators. Then reduce the fraction to lowest terms if possible.
\left(x-\frac{3}{14}\right)^{2}=\frac{121}{196}
Factor x^{2}-\frac{3}{7}x+\frac{9}{196}. 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}{14}\right)^{2}}=\sqrt{\frac{121}{196}}
Take the square root of both sides of the equation.
x-\frac{3}{14}=\frac{11}{14} x-\frac{3}{14}=-\frac{11}{14}
Simplify.
x=1 x=-\frac{4}{7}
Add \frac{3}{14} to both sides of the equation.
Examples
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{ x } ^ { 2 } - 4 x - 5 = 0
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4 \sin \theta \cos \theta = 2 \sin \theta
Linear equation
y = 3x + 4
Arithmetic
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Matrix
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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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