Solve 2*5=-x^2

$$2 \cdot 5 = - { x }^{ 2 }$$

Solve for x (complex solution)

$$x=-\sqrt{10}i\approx -0-3.16227766i$$

$$x=\sqrt{10}i\approx 3.16227766i$$

Steps by Finding Square Root

Multiply 2 and 5 to get 10.

$$10=-x^{2}$$

Swap sides so that all variable terms are on the left hand side.

$$-x^{2}=10$$

Divide both sides by -1.

$$x^{2}=-10$$

The equation is now solved.

$$x=\sqrt{10}i x=-\sqrt{10}i$$

Steps Using the Quadratic Formula

Multiply 2 and 5 to get 10.

$$10=-x^{2}$$

Swap sides so that all variable terms are on the left hand side.

$$-x^{2}=10$$

Subtract 10 from both sides.

$$-x^{2}-10=0$$

This equation is in standard form: ax^{2}+bx+c=0. Substitute -1 for a, 0 for b, and -10 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.

$$x=\frac{0±\sqrt{0^{2}-4\left(-1\right)\left(-10\right)}}{2\left(-1\right)}$$

Square 0.

$$x=\frac{0±\sqrt{-4\left(-1\right)\left(-10\right)}}{2\left(-1\right)}$$

Multiply -4 times -1.

$$x=\frac{0±\sqrt{4\left(-10\right)}}{2\left(-1\right)}$$

Multiply 4 times -10.

$$x=\frac{0±\sqrt{-40}}{2\left(-1\right)}$$

Take the square root of -40.

$$x=\frac{0±2\sqrt{10}i}{2\left(-1\right)}$$

Multiply 2 times -1.

$$x=\frac{0±2\sqrt{10}i}{-2}$$

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

$$x=-\sqrt{10}i$$

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

$$x=\sqrt{10}i$$

The equation is now solved.

$$x=-\sqrt{10}i x=\sqrt{10}i$$