Solve 2x^2-32x+192=0

$$2 { x }^{ 2 } -32x+192=0$$

Solve for x (complex solution)

$$x=8+4\sqrt{2}i\approx 8+5.656854249i$$

$$x=-4\sqrt{2}i+8\approx 8-5.656854249i$$

Steps Using the Quadratic Formula

All equations of the form ax^{2}+bx+c=0 can be solved using the quadratic formula: \frac{-b±\sqrt{b^{2}-4ac}}{2a}. The quadratic formula gives two solutions, one when ± is addition and one when it is subtraction.

$$2x^{2}-32x+192=0$$

This equation is in standard form: ax^{2}+bx+c=0. Substitute 2 for a, -32 for b, and 192 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.

$$x=\frac{-\left(-32\right)±\sqrt{\left(-32\right)^{2}-4\times 2\times 192}}{2\times 2}$$

Square -32.

$$x=\frac{-\left(-32\right)±\sqrt{1024-4\times 2\times 192}}{2\times 2}$$

Multiply -4 times 2.

$$x=\frac{-\left(-32\right)±\sqrt{1024-8\times 192}}{2\times 2}$$

Multiply -8 times 192.

$$x=\frac{-\left(-32\right)±\sqrt{1024-1536}}{2\times 2}$$

Add 1024 to -1536.

$$x=\frac{-\left(-32\right)±\sqrt{-512}}{2\times 2}$$

Take the square root of -512.

$$x=\frac{-\left(-32\right)±16\sqrt{2}i}{2\times 2}$$

The opposite of -32 is 32.

$$x=\frac{32±16\sqrt{2}i}{2\times 2}$$

Multiply 2 times 2.

$$x=\frac{32±16\sqrt{2}i}{4}$$

Now solve the equation x=\frac{32±16\sqrt{2}i}{4} when ± is plus. Add 32 to 16i\sqrt{2}.

$$x=\frac{32+2^{\frac{9}{2}}i}{4}$$

Divide 32+i\times 2^{\frac{9}{2}} by 4.

$$x=8+2^{\frac{5}{2}}i$$

Now solve the equation x=\frac{32±16\sqrt{2}i}{4} when ± is minus. Subtract 16i\sqrt{2} from 32.

$$x=\frac{-2^{\frac{9}{2}}i+32}{4}$$

Divide 32-i\times 2^{\frac{9}{2}} by 4.

$$x=-2^{\frac{5}{2}}i+8$$

The equation is now solved.

$$x=8+2^{\frac{5}{2}}i x=-2^{\frac{5}{2}}i+8$$

Steps for Completing the Square

Quadratic equations such as this one can be solved by completing the square. In order to complete the square, the equation must first be in the form x^{2}+bx=c.

$$2x^{2}-32x+192=0$$

Subtract 192 from both sides of the equation.

$$2x^{2}-32x+192-192=-192$$

Subtracting 192 from itself leaves 0.

$$2x^{2}-32x=-192$$

Divide both sides by 2.

$$\frac{2x^{2}-32x}{2}=-\frac{192}{2}$$

Dividing by 2 undoes the multiplication by 2.

$$x^{2}+\left(-\frac{32}{2}\right)x=-\frac{192}{2}$$

Divide -32 by 2.

$$x^{2}-16x=-\frac{192}{2}$$

Divide -192 by 2.

$$x^{2}-16x=-96$$

Divide -16, the coefficient of the x term, by 2 to get -8. Then add the square of -8 to both sides of the equation. This step makes the left hand side of the equation a perfect square.

$$x^{2}-16x+\left(-8\right)^{2}=-96+\left(-8\right)^{2}$$

Square -8.

$$x^{2}-16x+64=-96+64$$

Add -96 to 64.

$$x^{2}-16x+64=-32$$

Factor x^{2}-16x+64. In general, when x^{2}+bx+c is a perfect square, it can always be factored as \left(x+\frac{b}{2}\right)^{2}.

$$\left(x-8\right)^{2}=-32$$

Take the square root of both sides of the equation.

$$\sqrt{\left(x-8\right)^{2}}=\sqrt{-32}$$

Simplify.

$$x-8=4\sqrt{2}i x-8=-4\sqrt{2}i$$

Add 8 to both sides of the equation.

$$x=8+2^{\frac{5}{2}}i x=-2^{\frac{5}{2}}i+8$$