Solve for x
x = \frac{\sqrt{67109}}{10} \approx 25.905404841
x = -\frac{\sqrt{67109}}{10} \approx -25.905404841
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15\left(25.3^{2}-x^{2}\right)=-30\times 15.5
Multiply \frac{1}{2} and 30 to get 15.
15\left(640.09-x^{2}\right)=-30\times 15.5
Calculate 25.3 to the power of 2 and get 640.09.
9601.35-15x^{2}=-30\times 15.5
Use the distributive property to multiply 15 by 640.09-x^{2}.
9601.35-15x^{2}=-465
Multiply -30 and 15.5 to get -465.
-15x^{2}=-465-9601.35
Subtract 9601.35 from both sides.
-15x^{2}=-10066.35
Subtract 9601.35 from -465 to get -10066.35.
x^{2}=\frac{-10066.35}{-15}
Divide both sides by -15.
x^{2}=\frac{-1006635}{-1500}
Expand \frac{-10066.35}{-15} by multiplying both numerator and the denominator by 100.
x^{2}=\frac{67109}{100}
Reduce the fraction \frac{-1006635}{-1500} to lowest terms by extracting and canceling out -15.
x=\frac{\sqrt{67109}}{10} x=-\frac{\sqrt{67109}}{10}
Take the square root of both sides of the equation.
15\left(25.3^{2}-x^{2}\right)=-30\times 15.5
Multiply \frac{1}{2} and 30 to get 15.
15\left(640.09-x^{2}\right)=-30\times 15.5
Calculate 25.3 to the power of 2 and get 640.09.
9601.35-15x^{2}=-30\times 15.5
Use the distributive property to multiply 15 by 640.09-x^{2}.
9601.35-15x^{2}=-465
Multiply -30 and 15.5 to get -465.
9601.35-15x^{2}+465=0
Add 465 to both sides.
10066.35-15x^{2}=0
Add 9601.35 and 465 to get 10066.35.
-15x^{2}+10066.35=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\left(-15\right)\times 10066.35}}{2\left(-15\right)}
This equation is in standard form: ax^{2}+bx+c=0. Substitute -15 for a, 0 for b, and 10066.35 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{0±\sqrt{-4\left(-15\right)\times 10066.35}}{2\left(-15\right)}
Square 0.
x=\frac{0±\sqrt{60\times 10066.35}}{2\left(-15\right)}
Multiply -4 times -15.
x=\frac{0±\sqrt{603981}}{2\left(-15\right)}
Multiply 60 times 10066.35.
x=\frac{0±3\sqrt{67109}}{2\left(-15\right)}
Take the square root of 603981.
x=\frac{0±3\sqrt{67109}}{-30}
Multiply 2 times -15.
x=-\frac{\sqrt{67109}}{10}
Now solve the equation x=\frac{0±3\sqrt{67109}}{-30} when ± is plus.
x=\frac{\sqrt{67109}}{10}
Now solve the equation x=\frac{0±3\sqrt{67109}}{-30} when ± is minus.
x=-\frac{\sqrt{67109}}{10} x=\frac{\sqrt{67109}}{10}
The equation is now solved.
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