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x\times 3+\left(x-4\right)\left(x-3\right)=2x\left(x-4\right)
Variable x cannot be equal to any of the values 0,4 since division by zero is not defined. Multiply both sides of the equation by x\left(x-4\right), the least common multiple of x-4,x.
x\times 3+x^{2}-7x+12=2x\left(x-4\right)
Use the distributive property to multiply x-4 by x-3 and combine like terms.
-4x+x^{2}+12=2x\left(x-4\right)
Combine x\times 3 and -7x to get -4x.
-4x+x^{2}+12=2x^{2}-8x
Use the distributive property to multiply 2x by x-4.
-4x+x^{2}+12-2x^{2}=-8x
Subtract 2x^{2} from both sides.
-4x-x^{2}+12=-8x
Combine x^{2} and -2x^{2} to get -x^{2}.
-4x-x^{2}+12+8x=0
Add 8x to both sides.
4x-x^{2}+12=0
Combine -4x and 8x to get 4x.
-x^{2}+4x+12=0
Rearrange the polynomial to put it in standard form. Place the terms in order from highest to lowest power.
a+b=4 ab=-12=-12
To solve the equation, factor the left hand side by grouping. First, left hand side needs to be rewritten as -x^{2}+ax+bx+12. To find a and b, set up a system to be solved.
-1,12 -2,6 -3,4
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 -12.
-1+12=11 -2+6=4 -3+4=1
Calculate the sum for each pair.
a=6 b=-2
The solution is the pair that gives sum 4.
\left(-x^{2}+6x\right)+\left(-2x+12\right)
Rewrite -x^{2}+4x+12 as \left(-x^{2}+6x\right)+\left(-2x+12\right).
-x\left(x-6\right)-2\left(x-6\right)
Factor out -x in the first and -2 in the second group.
\left(x-6\right)\left(-x-2\right)
Factor out common term x-6 by using distributive property.
x=6 x=-2
To find equation solutions, solve x-6=0 and -x-2=0.
x\times 3+\left(x-4\right)\left(x-3\right)=2x\left(x-4\right)
Variable x cannot be equal to any of the values 0,4 since division by zero is not defined. Multiply both sides of the equation by x\left(x-4\right), the least common multiple of x-4,x.
x\times 3+x^{2}-7x+12=2x\left(x-4\right)
Use the distributive property to multiply x-4 by x-3 and combine like terms.
-4x+x^{2}+12=2x\left(x-4\right)
Combine x\times 3 and -7x to get -4x.
-4x+x^{2}+12=2x^{2}-8x
Use the distributive property to multiply 2x by x-4.
-4x+x^{2}+12-2x^{2}=-8x
Subtract 2x^{2} from both sides.
-4x-x^{2}+12=-8x
Combine x^{2} and -2x^{2} to get -x^{2}.
-4x-x^{2}+12+8x=0
Add 8x to both sides.
4x-x^{2}+12=0
Combine -4x and 8x to get 4x.
-x^{2}+4x+12=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{-4±\sqrt{4^{2}-4\left(-1\right)\times 12}}{2\left(-1\right)}
This equation is in standard form: ax^{2}+bx+c=0. Substitute -1 for a, 4 for b, and 12 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-4±\sqrt{16-4\left(-1\right)\times 12}}{2\left(-1\right)}
Square 4.
x=\frac{-4±\sqrt{16+4\times 12}}{2\left(-1\right)}
Multiply -4 times -1.
x=\frac{-4±\sqrt{16+48}}{2\left(-1\right)}
Multiply 4 times 12.
x=\frac{-4±\sqrt{64}}{2\left(-1\right)}
Add 16 to 48.
x=\frac{-4±8}{2\left(-1\right)}
Take the square root of 64.
x=\frac{-4±8}{-2}
Multiply 2 times -1.
x=\frac{4}{-2}
Now solve the equation x=\frac{-4±8}{-2} when ± is plus. Add -4 to 8.
x=-2
Divide 4 by -2.
x=-\frac{12}{-2}
Now solve the equation x=\frac{-4±8}{-2} when ± is minus. Subtract 8 from -4.
x=6
Divide -12 by -2.
x=-2 x=6
The equation is now solved.
x\times 3+\left(x-4\right)\left(x-3\right)=2x\left(x-4\right)
Variable x cannot be equal to any of the values 0,4 since division by zero is not defined. Multiply both sides of the equation by x\left(x-4\right), the least common multiple of x-4,x.
x\times 3+x^{2}-7x+12=2x\left(x-4\right)
Use the distributive property to multiply x-4 by x-3 and combine like terms.
-4x+x^{2}+12=2x\left(x-4\right)
Combine x\times 3 and -7x to get -4x.
-4x+x^{2}+12=2x^{2}-8x
Use the distributive property to multiply 2x by x-4.
-4x+x^{2}+12-2x^{2}=-8x
Subtract 2x^{2} from both sides.
-4x-x^{2}+12=-8x
Combine x^{2} and -2x^{2} to get -x^{2}.
-4x-x^{2}+12+8x=0
Add 8x to both sides.
4x-x^{2}+12=0
Combine -4x and 8x to get 4x.
4x-x^{2}=-12
Subtract 12 from both sides. Anything subtracted from zero gives its negation.
-x^{2}+4x=-12
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}+4x}{-1}=-\frac{12}{-1}
Divide both sides by -1.
x^{2}+\frac{4}{-1}x=-\frac{12}{-1}
Dividing by -1 undoes the multiplication by -1.
x^{2}-4x=-\frac{12}{-1}
Divide 4 by -1.
x^{2}-4x=12
Divide -12 by -1.
x^{2}-4x+\left(-2\right)^{2}=12+\left(-2\right)^{2}
Divide -4, the coefficient of the x term, by 2 to get -2. Then add the square of -2 to both sides of the equation. This step makes the left hand side of the equation a perfect square.
x^{2}-4x+4=12+4
Square -2.
x^{2}-4x+4=16
Add 12 to 4.
\left(x-2\right)^{2}=16
Factor x^{2}-4x+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-2\right)^{2}}=\sqrt{16}
Take the square root of both sides of the equation.
x-2=4 x-2=-4
Simplify.
x=6 x=-2
Add 2 to both sides of the equation.