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240=x\left(x+14\right)
Variable x cannot be equal to -14 since division by zero is not defined. Multiply both sides of the equation by x+14.
240=x^{2}+14x
Use the distributive property to multiply x by x+14.
x^{2}+14x=240
Swap sides so that all variable terms are on the left hand side.
x^{2}+14x-240=0
Subtract 240 from both sides.
x=\frac{-14±\sqrt{14^{2}-4\left(-240\right)}}{2}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 1 for a, 14 for b, and -240 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-14±\sqrt{196-4\left(-240\right)}}{2}
Square 14.
x=\frac{-14±\sqrt{196+960}}{2}
Multiply -4 times -240.
x=\frac{-14±\sqrt{1156}}{2}
Add 196 to 960.
x=\frac{-14±34}{2}
Take the square root of 1156.
x=\frac{20}{2}
Now solve the equation x=\frac{-14±34}{2} when ± is plus. Add -14 to 34.
x=10
Divide 20 by 2.
x=-\frac{48}{2}
Now solve the equation x=\frac{-14±34}{2} when ± is minus. Subtract 34 from -14.
x=-24
Divide -48 by 2.
x=10 x=-24
The equation is now solved.
240=x\left(x+14\right)
Variable x cannot be equal to -14 since division by zero is not defined. Multiply both sides of the equation by x+14.
240=x^{2}+14x
Use the distributive property to multiply x by x+14.
x^{2}+14x=240
Swap sides so that all variable terms are on the left hand side.
x^{2}+14x+7^{2}=240+7^{2}
Divide 14, the coefficient of the x term, by 2 to get 7. Then add the square of 7 to both sides of the equation. This step makes the left hand side of the equation a perfect square.
x^{2}+14x+49=240+49
Square 7.
x^{2}+14x+49=289
Add 240 to 49.
\left(x+7\right)^{2}=289
Factor x^{2}+14x+49. 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+7\right)^{2}}=\sqrt{289}
Take the square root of both sides of the equation.
x+7=17 x+7=-17
Simplify.
x=10 x=-24
Subtract 7 from both sides of the equation.