Skip to main content
Solve for x
Tick mark Image
Graph

Similar Problems from Web Search

Share

9-x^{2}=0x\left(x-3\right)
Variable x cannot be equal to 3 since division by zero is not defined. Multiply both sides of the equation by x-3.
9-x^{2}=0
Anything times zero gives zero.
-x^{2}=-9
Subtract 9 from both sides. Anything subtracted from zero gives its negation.
x^{2}=\frac{-9}{-1}
Divide both sides by -1.
x^{2}=9
Fraction \frac{-9}{-1} can be simplified to 9 by removing the negative sign from both the numerator and the denominator.
x=3 x=-3
Take the square root of both sides of the equation.
x=-3
Variable x cannot be equal to 3.
9-x^{2}=0x\left(x-3\right)
Variable x cannot be equal to 3 since division by zero is not defined. Multiply both sides of the equation by x-3.
9-x^{2}=0
Anything times zero gives zero.
-x^{2}+9=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(-1\right)\times 9}}{2\left(-1\right)}
This equation is in standard form: ax^{2}+bx+c=0. Substitute -1 for a, 0 for b, and 9 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{0±\sqrt{-4\left(-1\right)\times 9}}{2\left(-1\right)}
Square 0.
x=\frac{0±\sqrt{4\times 9}}{2\left(-1\right)}
Multiply -4 times -1.
x=\frac{0±\sqrt{36}}{2\left(-1\right)}
Multiply 4 times 9.
x=\frac{0±6}{2\left(-1\right)}
Take the square root of 36.
x=\frac{0±6}{-2}
Multiply 2 times -1.
x=-3
Now solve the equation x=\frac{0±6}{-2} when ± is plus. Divide 6 by -2.
x=3
Now solve the equation x=\frac{0±6}{-2} when ± is minus. Divide -6 by -2.
x=-3 x=3
The equation is now solved.
x=-3
Variable x cannot be equal to 3.