Solve x^2=0.64

$${ x }^{ 2 } =0.64$$

Solve for x

$$x=0.8$$

$$x=-0.8$$

Steps Using Difference of Squares

Subtract 0.64 from both sides.

$$x^{2}-0.64=0$$

Consider x^{2}-0.64. Rewrite x^{2}-0.64 as x^{2}-\left(\frac{4}{5}\right)^{2}. The difference of squares can be factored using the rule: a^{2}-b^{2}=\left(a-b\right)\left(a+b\right).

$$\left(x-\frac{4}{5}\right)\left(x+\frac{4}{5}\right)=0$$

To find equation solutions, solve x-\frac{4}{5}=0 and x+\frac{4}{5}=0.

$$x=\frac{4}{5} x=-\frac{4}{5}$$

Steps by Finding Square Root

Take the square root of both sides of the equation.

$$x=\frac{4}{5} x=-\frac{4}{5}$$

Steps Using the Quadratic Formula

Subtract 0.64 from both sides.

$$x^{2}-0.64=0$$

This equation is in standard form: ax^{2}+bx+c=0. Substitute 1 for a, 0 for b, and -0.64 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.

$$x=\frac{0±\sqrt{0^{2}-4\left(-0.64\right)}}{2}$$

Square 0.

$$x=\frac{0±\sqrt{-4\left(-0.64\right)}}{2}$$

Multiply -4 times -0.64.

$$x=\frac{0±\sqrt{2.56}}{2}$$

Take the square root of 2.56.

$$x=\frac{0±\frac{8}{5}}{2}$$

Now solve the equation x=\frac{0±\frac{8}{5}}{2} when ± is plus.

$$x=\frac{4}{5}$$

Now solve the equation x=\frac{0±\frac{8}{5}}{2} when ± is minus.

$$x=-\frac{4}{5}$$

The equation is now solved.

$$x=\frac{4}{5} x=-\frac{4}{5}$$