Solve -x^2+7*-10=0

$$- { x }^{ 2 } +7 \times -10=0$$

Solve for x (complex solution)

$$x=-\sqrt{70}i\approx -0-8.366600265i$$

$$x=\sqrt{70}i\approx 8.366600265i$$

Steps by Finding Square Root

Multiply 7 and -10 to get -70.

$$-x^{2}-70=0$$

Add 70 to both sides. Anything plus zero gives itself.

$$-x^{2}=70$$

Divide both sides by -1.

$$x^{2}=-70$$

The equation is now solved.

$$x=\sqrt{70}i x=-\sqrt{70}i$$

Steps Using the Quadratic Formula

Multiply 7 and -10 to get -70.

$$-x^{2}-70=0$$

This equation is in standard form: ax^{2}+bx+c=0. Substitute -1 for a, 0 for b, and -70 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.

$$x=\frac{0±\sqrt{0^{2}-4\left(-1\right)\left(-70\right)}}{2\left(-1\right)}$$

Square 0.

$$x=\frac{0±\sqrt{-4\left(-1\right)\left(-70\right)}}{2\left(-1\right)}$$

Multiply -4 times -1.

$$x=\frac{0±\sqrt{4\left(-70\right)}}{2\left(-1\right)}$$

Multiply 4 times -70.

$$x=\frac{0±\sqrt{-280}}{2\left(-1\right)}$$

Take the square root of -280.

$$x=\frac{0±2\sqrt{70}i}{2\left(-1\right)}$$

Multiply 2 times -1.

$$x=\frac{0±2\sqrt{70}i}{-2}$$

Now solve the equation x=\frac{0±2\sqrt{70}i}{-2} when ± is plus.

$$x=-\sqrt{70}i$$

Now solve the equation x=\frac{0±2\sqrt{70}i}{-2} when ± is minus.

$$x=\sqrt{70}i$$

The equation is now solved.

$$x=-\sqrt{70}i x=\sqrt{70}i$$