Solve for x (complex solution)
x=\sqrt{10}-1\approx 2.16227766
x=-\left(\sqrt{10}+1\right)\approx -4.16227766
Solve for x
x=\sqrt{10}-1\approx 2.16227766
x=-\sqrt{10}-1\approx -4.16227766
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\left(x+5\right)\times 6+\left(2x+6\right)\times 3=2\left(x+3\right)\left(x+5\right)
Variable x cannot be equal to any of the values -5,-3 since division by zero is not defined. Multiply both sides of the equation by 2\left(x+3\right)\left(x+5\right), the least common multiple of 2x+6,x+5.
6x+30+\left(2x+6\right)\times 3=2\left(x+3\right)\left(x+5\right)
Use the distributive property to multiply x+5 by 6.
6x+30+6x+18=2\left(x+3\right)\left(x+5\right)
Use the distributive property to multiply 2x+6 by 3.
12x+30+18=2\left(x+3\right)\left(x+5\right)
Combine 6x and 6x to get 12x.
12x+48=2\left(x+3\right)\left(x+5\right)
Add 30 and 18 to get 48.
12x+48=\left(2x+6\right)\left(x+5\right)
Use the distributive property to multiply 2 by x+3.
12x+48=2x^{2}+16x+30
Use the distributive property to multiply 2x+6 by x+5 and combine like terms.
12x+48-2x^{2}=16x+30
Subtract 2x^{2} from both sides.
12x+48-2x^{2}-16x=30
Subtract 16x from both sides.
-4x+48-2x^{2}=30
Combine 12x and -16x to get -4x.
-4x+48-2x^{2}-30=0
Subtract 30 from both sides.
-4x+18-2x^{2}=0
Subtract 30 from 48 to get 18.
-2x^{2}-4x+18=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(-4\right)±\sqrt{\left(-4\right)^{2}-4\left(-2\right)\times 18}}{2\left(-2\right)}
This equation is in standard form: ax^{2}+bx+c=0. Substitute -2 for a, -4 for b, and 18 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-\left(-4\right)±\sqrt{16-4\left(-2\right)\times 18}}{2\left(-2\right)}
Square -4.
x=\frac{-\left(-4\right)±\sqrt{16+8\times 18}}{2\left(-2\right)}
Multiply -4 times -2.
x=\frac{-\left(-4\right)±\sqrt{16+144}}{2\left(-2\right)}
Multiply 8 times 18.
x=\frac{-\left(-4\right)±\sqrt{160}}{2\left(-2\right)}
Add 16 to 144.
x=\frac{-\left(-4\right)±4\sqrt{10}}{2\left(-2\right)}
Take the square root of 160.
x=\frac{4±4\sqrt{10}}{2\left(-2\right)}
The opposite of -4 is 4.
x=\frac{4±4\sqrt{10}}{-4}
Multiply 2 times -2.
x=\frac{4\sqrt{10}+4}{-4}
Now solve the equation x=\frac{4±4\sqrt{10}}{-4} when ± is plus. Add 4 to 4\sqrt{10}.
x=-\left(\sqrt{10}+1\right)
Divide 4+4\sqrt{10} by -4.
x=\frac{4-4\sqrt{10}}{-4}
Now solve the equation x=\frac{4±4\sqrt{10}}{-4} when ± is minus. Subtract 4\sqrt{10} from 4.
x=\sqrt{10}-1
Divide 4-4\sqrt{10} by -4.
x=-\left(\sqrt{10}+1\right) x=\sqrt{10}-1
The equation is now solved.
\left(x+5\right)\times 6+\left(2x+6\right)\times 3=2\left(x+3\right)\left(x+5\right)
Variable x cannot be equal to any of the values -5,-3 since division by zero is not defined. Multiply both sides of the equation by 2\left(x+3\right)\left(x+5\right), the least common multiple of 2x+6,x+5.
6x+30+\left(2x+6\right)\times 3=2\left(x+3\right)\left(x+5\right)
Use the distributive property to multiply x+5 by 6.
6x+30+6x+18=2\left(x+3\right)\left(x+5\right)
Use the distributive property to multiply 2x+6 by 3.
12x+30+18=2\left(x+3\right)\left(x+5\right)
Combine 6x and 6x to get 12x.
12x+48=2\left(x+3\right)\left(x+5\right)
Add 30 and 18 to get 48.
12x+48=\left(2x+6\right)\left(x+5\right)
Use the distributive property to multiply 2 by x+3.
12x+48=2x^{2}+16x+30
Use the distributive property to multiply 2x+6 by x+5 and combine like terms.
12x+48-2x^{2}=16x+30
Subtract 2x^{2} from both sides.
12x+48-2x^{2}-16x=30
Subtract 16x from both sides.
-4x+48-2x^{2}=30
Combine 12x and -16x to get -4x.
-4x-2x^{2}=30-48
Subtract 48 from both sides.
-4x-2x^{2}=-18
Subtract 48 from 30 to get -18.
-2x^{2}-4x=-18
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{-2x^{2}-4x}{-2}=-\frac{18}{-2}
Divide both sides by -2.
x^{2}+\left(-\frac{4}{-2}\right)x=-\frac{18}{-2}
Dividing by -2 undoes the multiplication by -2.
x^{2}+2x=-\frac{18}{-2}
Divide -4 by -2.
x^{2}+2x=9
Divide -18 by -2.
x^{2}+2x+1^{2}=9+1^{2}
Divide 2, the coefficient of the x term, by 2 to get 1. Then add the square of 1 to both sides of the equation. This step makes the left hand side of the equation a perfect square.
x^{2}+2x+1=9+1
Square 1.
x^{2}+2x+1=10
Add 9 to 1.
\left(x+1\right)^{2}=10
Factor x^{2}+2x+1. 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+1\right)^{2}}=\sqrt{10}
Take the square root of both sides of the equation.
x+1=\sqrt{10} x+1=-\sqrt{10}
Simplify.
x=\sqrt{10}-1 x=-\sqrt{10}-1
Subtract 1 from both sides of the equation.
\left(x+5\right)\times 6+\left(2x+6\right)\times 3=2\left(x+3\right)\left(x+5\right)
Variable x cannot be equal to any of the values -5,-3 since division by zero is not defined. Multiply both sides of the equation by 2\left(x+3\right)\left(x+5\right), the least common multiple of 2x+6,x+5.
6x+30+\left(2x+6\right)\times 3=2\left(x+3\right)\left(x+5\right)
Use the distributive property to multiply x+5 by 6.
6x+30+6x+18=2\left(x+3\right)\left(x+5\right)
Use the distributive property to multiply 2x+6 by 3.
12x+30+18=2\left(x+3\right)\left(x+5\right)
Combine 6x and 6x to get 12x.
12x+48=2\left(x+3\right)\left(x+5\right)
Add 30 and 18 to get 48.
12x+48=\left(2x+6\right)\left(x+5\right)
Use the distributive property to multiply 2 by x+3.
12x+48=2x^{2}+16x+30
Use the distributive property to multiply 2x+6 by x+5 and combine like terms.
12x+48-2x^{2}=16x+30
Subtract 2x^{2} from both sides.
12x+48-2x^{2}-16x=30
Subtract 16x from both sides.
-4x+48-2x^{2}=30
Combine 12x and -16x to get -4x.
-4x+48-2x^{2}-30=0
Subtract 30 from both sides.
-4x+18-2x^{2}=0
Subtract 30 from 48 to get 18.
-2x^{2}-4x+18=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(-4\right)±\sqrt{\left(-4\right)^{2}-4\left(-2\right)\times 18}}{2\left(-2\right)}
This equation is in standard form: ax^{2}+bx+c=0. Substitute -2 for a, -4 for b, and 18 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-\left(-4\right)±\sqrt{16-4\left(-2\right)\times 18}}{2\left(-2\right)}
Square -4.
x=\frac{-\left(-4\right)±\sqrt{16+8\times 18}}{2\left(-2\right)}
Multiply -4 times -2.
x=\frac{-\left(-4\right)±\sqrt{16+144}}{2\left(-2\right)}
Multiply 8 times 18.
x=\frac{-\left(-4\right)±\sqrt{160}}{2\left(-2\right)}
Add 16 to 144.
x=\frac{-\left(-4\right)±4\sqrt{10}}{2\left(-2\right)}
Take the square root of 160.
x=\frac{4±4\sqrt{10}}{2\left(-2\right)}
The opposite of -4 is 4.
x=\frac{4±4\sqrt{10}}{-4}
Multiply 2 times -2.
x=\frac{4\sqrt{10}+4}{-4}
Now solve the equation x=\frac{4±4\sqrt{10}}{-4} when ± is plus. Add 4 to 4\sqrt{10}.
x=-\left(\sqrt{10}+1\right)
Divide 4+4\sqrt{10} by -4.
x=\frac{4-4\sqrt{10}}{-4}
Now solve the equation x=\frac{4±4\sqrt{10}}{-4} when ± is minus. Subtract 4\sqrt{10} from 4.
x=\sqrt{10}-1
Divide 4-4\sqrt{10} by -4.
x=-\left(\sqrt{10}+1\right) x=\sqrt{10}-1
The equation is now solved.
\left(x+5\right)\times 6+\left(2x+6\right)\times 3=2\left(x+3\right)\left(x+5\right)
Variable x cannot be equal to any of the values -5,-3 since division by zero is not defined. Multiply both sides of the equation by 2\left(x+3\right)\left(x+5\right), the least common multiple of 2x+6,x+5.
6x+30+\left(2x+6\right)\times 3=2\left(x+3\right)\left(x+5\right)
Use the distributive property to multiply x+5 by 6.
6x+30+6x+18=2\left(x+3\right)\left(x+5\right)
Use the distributive property to multiply 2x+6 by 3.
12x+30+18=2\left(x+3\right)\left(x+5\right)
Combine 6x and 6x to get 12x.
12x+48=2\left(x+3\right)\left(x+5\right)
Add 30 and 18 to get 48.
12x+48=\left(2x+6\right)\left(x+5\right)
Use the distributive property to multiply 2 by x+3.
12x+48=2x^{2}+16x+30
Use the distributive property to multiply 2x+6 by x+5 and combine like terms.
12x+48-2x^{2}=16x+30
Subtract 2x^{2} from both sides.
12x+48-2x^{2}-16x=30
Subtract 16x from both sides.
-4x+48-2x^{2}=30
Combine 12x and -16x to get -4x.
-4x-2x^{2}=30-48
Subtract 48 from both sides.
-4x-2x^{2}=-18
Subtract 48 from 30 to get -18.
-2x^{2}-4x=-18
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{-2x^{2}-4x}{-2}=-\frac{18}{-2}
Divide both sides by -2.
x^{2}+\left(-\frac{4}{-2}\right)x=-\frac{18}{-2}
Dividing by -2 undoes the multiplication by -2.
x^{2}+2x=-\frac{18}{-2}
Divide -4 by -2.
x^{2}+2x=9
Divide -18 by -2.
x^{2}+2x+1^{2}=9+1^{2}
Divide 2, the coefficient of the x term, by 2 to get 1. Then add the square of 1 to both sides of the equation. This step makes the left hand side of the equation a perfect square.
x^{2}+2x+1=9+1
Square 1.
x^{2}+2x+1=10
Add 9 to 1.
\left(x+1\right)^{2}=10
Factor x^{2}+2x+1. 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+1\right)^{2}}=\sqrt{10}
Take the square root of both sides of the equation.
x+1=\sqrt{10} x+1=-\sqrt{10}
Simplify.
x=\sqrt{10}-1 x=-\sqrt{10}-1
Subtract 1 from both sides of the equation.
Examples
Quadratic equation
{ 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}