Solve x^2-11=0

$${ x }^{ 2 } -11=0$$

Solve for x

$$x=\sqrt{11}\approx 3.31662479$$

$$x=-\sqrt{11}\approx -3.31662479$$

Steps by Finding Square Root

Add 11 to both sides. Anything plus zero gives itself.

$$x^{2}=11$$

Take the square root of both sides of the equation.

$$x=\sqrt{11} x=-\sqrt{11}$$

Steps Using the Quadratic Formula

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.

$$x^{2}-11=0$$

This equation is in standard form: ax^{2}+bx+c=0. Substitute 1 for a, 0 for b, and -11 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.

$$x=\frac{0±\sqrt{0^{2}-4\left(-11\right)}}{2}$$

Square 0.

$$x=\frac{0±\sqrt{-4\left(-11\right)}}{2}$$

Multiply -4 times -11.

$$x=\frac{0±\sqrt{44}}{2}$$

Take the square root of 44.

$$x=\frac{0±2\sqrt{11}}{2}$$

Now solve the equation x=\frac{0±2\sqrt{11}}{2} when ± is plus.

$$x=\sqrt{11}$$

Now solve the equation x=\frac{0±2\sqrt{11}}{2} when ± is minus.

$$x=-\sqrt{11}$$

The equation is now solved.

$$x=\sqrt{11} x=-\sqrt{11}$$