Solve -x^2=25

$$- x ^ { 2 } = 25$$

Solve for x (complex solution)

$$x=-5i$$

$$x=5i$$

Steps by Finding Square Root

Divide both sides by -1.

$$x^{2}=-25$$

The equation is now solved.

$$x=5i x=-5i$$

Steps Using the Quadratic Formula

Subtract 25 from both sides.

$$-x^{2}-25=0$$

This equation is in standard form: ax^{2}+bx+c=0. Substitute -1 for a, 0 for b, and -25 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.

$$x=\frac{0±\sqrt{0^{2}-4\left(-1\right)\left(-25\right)}}{2\left(-1\right)}$$

Square 0.

$$x=\frac{0±\sqrt{-4\left(-1\right)\left(-25\right)}}{2\left(-1\right)}$$

Multiply -4 times -1.

$$x=\frac{0±\sqrt{4\left(-25\right)}}{2\left(-1\right)}$$

Multiply 4 times -25.

$$x=\frac{0±\sqrt{-100}}{2\left(-1\right)}$$

Take the square root of -100.

$$x=\frac{0±10i}{2\left(-1\right)}$$

Multiply 2 times -1.

$$x=\frac{0±10i}{-2}$$

Now solve the equation x=\frac{0±10i}{-2} when ± is plus.

$$x=-5i$$

Now solve the equation x=\frac{0±10i}{-2} when ± is minus.

$$x=5i$$

The equation is now solved.

$$x=-5i x=5i$$