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50+2\times 15=x\times 2x
Variable x cannot be equal to 0 since division by zero is not defined. Multiply both sides of the equation by 2x, the least common multiple of 2x,x.
50+30=x\times 2x
Multiply 2 and 15 to get 30.
80=x\times 2x
Add 50 and 30 to get 80.
80=x^{2}\times 2
Multiply x and x to get x^{2}.
x^{2}\times 2=80
Swap sides so that all variable terms are on the left hand side.
x^{2}=\frac{80}{2}
Divide both sides by 2.
x^{2}=40
Divide 80 by 2 to get 40.
x=2\sqrt{10} x=-2\sqrt{10}
Take the square root of both sides of the equation.
50+2\times 15=x\times 2x
Variable x cannot be equal to 0 since division by zero is not defined. Multiply both sides of the equation by 2x, the least common multiple of 2x,x.
50+30=x\times 2x
Multiply 2 and 15 to get 30.
80=x\times 2x
Add 50 and 30 to get 80.
80=x^{2}\times 2
Multiply x and x to get x^{2}.
x^{2}\times 2=80
Swap sides so that all variable terms are on the left hand side.
x^{2}\times 2-80=0
Subtract 80 from both sides.
2x^{2}-80=0
Quadratic equations like this one, with an x^{2} term but no x term, can still be solved using the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}, once they are put in standard form: ax^{2}+bx+c=0.
x=\frac{0±\sqrt{0^{2}-4\times 2\left(-80\right)}}{2\times 2}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 2 for a, 0 for b, and -80 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{0±\sqrt{-4\times 2\left(-80\right)}}{2\times 2}
Square 0.
x=\frac{0±\sqrt{-8\left(-80\right)}}{2\times 2}
Multiply -4 times 2.
x=\frac{0±\sqrt{640}}{2\times 2}
Multiply -8 times -80.
x=\frac{0±8\sqrt{10}}{2\times 2}
Take the square root of 640.
x=\frac{0±8\sqrt{10}}{4}
Multiply 2 times 2.
x=2\sqrt{10}
Now solve the equation x=\frac{0±8\sqrt{10}}{4} when ± is plus.
x=-2\sqrt{10}
Now solve the equation x=\frac{0±8\sqrt{10}}{4} when ± is minus.
x=2\sqrt{10} x=-2\sqrt{10}
The equation is now solved.