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x\times 3920+x\left(x+2\right)\times 224=\left(x+2\right)\times 3920
Variable x cannot be equal to any of the values -2,0 since division by zero is not defined. Multiply both sides of the equation by x\left(x+2\right), the least common multiple of x+2,x.
x\times 3920+\left(x^{2}+2x\right)\times 224=\left(x+2\right)\times 3920
Use the distributive property to multiply x by x+2.
x\times 3920+224x^{2}+448x=\left(x+2\right)\times 3920
Use the distributive property to multiply x^{2}+2x by 224.
4368x+224x^{2}=\left(x+2\right)\times 3920
Combine x\times 3920 and 448x to get 4368x.
4368x+224x^{2}=3920x+7840
Use the distributive property to multiply x+2 by 3920.
4368x+224x^{2}-3920x=7840
Subtract 3920x from both sides.
448x+224x^{2}=7840
Combine 4368x and -3920x to get 448x.
448x+224x^{2}-7840=0
Subtract 7840 from both sides.
224x^{2}+448x-7840=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{-448±\sqrt{448^{2}-4\times 224\left(-7840\right)}}{2\times 224}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 224 for a, 448 for b, and -7840 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-448±\sqrt{200704-4\times 224\left(-7840\right)}}{2\times 224}
Square 448.
x=\frac{-448±\sqrt{200704-896\left(-7840\right)}}{2\times 224}
Multiply -4 times 224.
x=\frac{-448±\sqrt{200704+7024640}}{2\times 224}
Multiply -896 times -7840.
x=\frac{-448±\sqrt{7225344}}{2\times 224}
Add 200704 to 7024640.
x=\frac{-448±2688}{2\times 224}
Take the square root of 7225344.
x=\frac{-448±2688}{448}
Multiply 2 times 224.
x=\frac{2240}{448}
Now solve the equation x=\frac{-448±2688}{448} when ± is plus. Add -448 to 2688.
x=5
Divide 2240 by 448.
x=-\frac{3136}{448}
Now solve the equation x=\frac{-448±2688}{448} when ± is minus. Subtract 2688 from -448.
x=-7
Divide -3136 by 448.
x=5 x=-7
The equation is now solved.
x\times 3920+x\left(x+2\right)\times 224=\left(x+2\right)\times 3920
Variable x cannot be equal to any of the values -2,0 since division by zero is not defined. Multiply both sides of the equation by x\left(x+2\right), the least common multiple of x+2,x.
x\times 3920+\left(x^{2}+2x\right)\times 224=\left(x+2\right)\times 3920
Use the distributive property to multiply x by x+2.
x\times 3920+224x^{2}+448x=\left(x+2\right)\times 3920
Use the distributive property to multiply x^{2}+2x by 224.
4368x+224x^{2}=\left(x+2\right)\times 3920
Combine x\times 3920 and 448x to get 4368x.
4368x+224x^{2}=3920x+7840
Use the distributive property to multiply x+2 by 3920.
4368x+224x^{2}-3920x=7840
Subtract 3920x from both sides.
448x+224x^{2}=7840
Combine 4368x and -3920x to get 448x.
224x^{2}+448x=7840
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{224x^{2}+448x}{224}=\frac{7840}{224}
Divide both sides by 224.
x^{2}+\frac{448}{224}x=\frac{7840}{224}
Dividing by 224 undoes the multiplication by 224.
x^{2}+2x=\frac{7840}{224}
Divide 448 by 224.
x^{2}+2x=35
Divide 7840 by 224.
x^{2}+2x+1^{2}=35+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=35+1
Square 1.
x^{2}+2x+1=36
Add 35 to 1.
\left(x+1\right)^{2}=36
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{36}
Take the square root of both sides of the equation.
x+1=6 x+1=-6
Simplify.
x=5 x=-7
Subtract 1 from both sides of the equation.