Solve x=4x^2

$$x = 4 x ^ { 2 }$$

Solve for x

$$x=\frac{1}{4}=0.25$$

$$x=0$$

Steps Using Factoring

Subtract 4x^{2} from both sides.

$$x-4x^{2}=0$$

Factor out x.

$$x\left(1-4x\right)=0$$

To find equation solutions, solve x=0 and 1-4x=0.

$$x=0 x=\frac{1}{4}$$

Steps Using the Quadratic Formula

Subtract 4x^{2} from both sides.

$$x-4x^{2}=0$$

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.

$$-4x^{2}+x=0$$

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

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

Take the square root of 1^{2}.

$$x=\frac{-1±1}{2\left(-4\right)}$$

Multiply 2 times -4.

$$x=\frac{-1±1}{-8}$$

Now solve the equation x=\frac{-1±1}{-8} when ± is plus. Add -1 to 1.

$$x=\frac{0}{-8}$$

Divide 0 by -8.

$$x=0$$

Now solve the equation x=\frac{-1±1}{-8} when ± is minus. Subtract 1 from -1.

$$x=-\frac{2}{-8}$$

Reduce the fraction \frac{-2}{-8} to lowest terms by extracting and canceling out 2.

$$x=\frac{1}{4}$$

The equation is now solved.

$$x=0 x=\frac{1}{4}$$

Steps for Completing the Square

Subtract 4x^{2} from both sides.

$$x-4x^{2}=0$$

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.

$$-4x^{2}+x=0$$

Divide both sides by -4.

$$\frac{-4x^{2}+x}{-4}=\frac{0}{-4}$$

Dividing by -4 undoes the multiplication by -4.

$$x^{2}+\frac{1}{-4}x=\frac{0}{-4}$$

Divide 1 by -4.

$$x^{2}-\frac{1}{4}x=\frac{0}{-4}$$

Divide 0 by -4.

$$x^{2}-\frac{1}{4}x=0$$

Divide -\frac{1}{4}, the coefficient of the x term, by 2 to get -\frac{1}{8}. Then add the square of -\frac{1}{8} to both sides of the equation. This step makes the left hand side of the equation a perfect square.

$$x^{2}-\frac{1}{4}x+\left(-\frac{1}{8}\right)^{2}=\left(-\frac{1}{8}\right)^{2}$$

Square -\frac{1}{8} by squaring both the numerator and the denominator of the fraction.

$$x^{2}-\frac{1}{4}x+\frac{1}{64}=\frac{1}{64}$$

Factor x^{2}-\frac{1}{4}x+\frac{1}{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}.

$$\left(x-\frac{1}{8}\right)^{2}=\frac{1}{64}$$

Take the square root of both sides of the equation.

$$\sqrt{\left(x-\frac{1}{8}\right)^{2}}=\sqrt{\frac{1}{64}}$$

Simplify.

$$x-\frac{1}{8}=\frac{1}{8} x-\frac{1}{8}=-\frac{1}{8}$$

Add \frac{1}{8} to both sides of the equation.

$$x=\frac{1}{4} x=0$$