Solve 9x^2+12+4=0

$$9 x ^ { 2 } + 12 + 4 = 0$$

Solve for x (complex solution)

$$x=-\frac{4}{3}i\approx -1.333333333i$$

$$x=\frac{4}{3}i\approx 1.333333333i$$

Steps by Finding Square Root

Add 12 and 4 to get 16.

$$9x^{2}+16=0$$

Subtract 16 from both sides. Anything subtracted from zero gives its negation.

$$9x^{2}=-16$$

Divide both sides by 9.

$$x^{2}=-\frac{16}{9}$$

The equation is now solved.

$$x=\frac{4}{3}i x=-\frac{4}{3}i$$

Steps Using the Quadratic Formula

Add 12 and 4 to get 16.

$$9x^{2}+16=0$$

This equation is in standard form: ax^{2}+bx+c=0. Substitute 9 for a, 0 for b, and 16 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.

$$x=\frac{0±\sqrt{0^{2}-4\times 9\times 16}}{2\times 9}$$

Square 0.

$$x=\frac{0±\sqrt{-4\times 9\times 16}}{2\times 9}$$

Multiply -4 times 9.

$$x=\frac{0±\sqrt{-36\times 16}}{2\times 9}$$

Multiply -36 times 16.

$$x=\frac{0±\sqrt{-576}}{2\times 9}$$

Take the square root of -576.

$$x=\frac{0±24i}{2\times 9}$$

Multiply 2 times 9.

$$x=\frac{0±24i}{18}$$

Now solve the equation x=\frac{0±24i}{18} when ± is plus.

$$x=\frac{4}{3}i$$

Now solve the equation x=\frac{0±24i}{18} when ± is minus.

$$x=-\frac{4}{3}i$$

The equation is now solved.

$$x=\frac{4}{3}i x=-\frac{4}{3}i$$