Solve for x
x=\frac{4\sqrt{265}}{265}\approx 0.245718047
x=-\frac{4\sqrt{265}}{265}\approx -0.245718047
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9+265x^{2}=25
Multiply both sides of the equation by 25.
265x^{2}=25-9
Subtract 9 from both sides.
265x^{2}=16
Subtract 9 from 25 to get 16.
x^{2}=\frac{16}{265}
Divide both sides by 265.
x=\frac{4\sqrt{265}}{265} x=-\frac{4\sqrt{265}}{265}
Take the square root of both sides of the equation.
9+265x^{2}=25
Multiply both sides of the equation by 25.
9+265x^{2}-25=0
Subtract 25 from both sides.
-16+265x^{2}=0
Subtract 25 from 9 to get -16.
265x^{2}-16=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 265\left(-16\right)}}{2\times 265}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 265 for a, 0 for b, and -16 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{0±\sqrt{-4\times 265\left(-16\right)}}{2\times 265}
Square 0.
x=\frac{0±\sqrt{-1060\left(-16\right)}}{2\times 265}
Multiply -4 times 265.
x=\frac{0±\sqrt{16960}}{2\times 265}
Multiply -1060 times -16.
x=\frac{0±8\sqrt{265}}{2\times 265}
Take the square root of 16960.
x=\frac{0±8\sqrt{265}}{530}
Multiply 2 times 265.
x=\frac{4\sqrt{265}}{265}
Now solve the equation x=\frac{0±8\sqrt{265}}{530} when ± is plus.
x=-\frac{4\sqrt{265}}{265}
Now solve the equation x=\frac{0±8\sqrt{265}}{530} when ± is minus.
x=\frac{4\sqrt{265}}{265} x=-\frac{4\sqrt{265}}{265}
The equation is now solved.
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