Solve 2x*4x=20

$$2x \times 4x=20$$

Solve for x

$$x = \frac{\sqrt{10}}{2} \approx 1.58113883$$

$$x = -\frac{\sqrt{10}}{2} \approx -1.58113883$$

Steps by Finding Square Root

Multiply x and x to get x^{2}.

$$2x^{2}\times 4=20$$

Multiply 2 and 4 to get 8.

$$8x^{2}=20$$

Divide both sides by 8.

$$x^{2}=\frac{20}{8}$$

Reduce the fraction \frac{20}{8} to lowest terms by extracting and canceling out 4.

$$x^{2}=\frac{5}{2}$$

Take the square root of both sides of the equation.

$$x=\frac{\sqrt{10}}{2} x=-\frac{\sqrt{10}}{2}$$

Steps Using the Quadratic Formula

Multiply x and x to get x^{2}.

$$2x^{2}\times 4=20$$

Multiply 2 and 4 to get 8.

$$8x^{2}=20$$

Subtract 20 from both sides.

$$8x^{2}-20=0$$

This equation is in standard form: ax^{2}+bx+c=0. Substitute 8 for a, 0 for b, and -20 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.

$$x=\frac{0±\sqrt{0^{2}-4\times 8\left(-20\right)}}{2\times 8}$$

Square 0.

$$x=\frac{0±\sqrt{-4\times 8\left(-20\right)}}{2\times 8}$$

Multiply -4 times 8.

$$x=\frac{0±\sqrt{-32\left(-20\right)}}{2\times 8}$$

Multiply -32 times -20.

$$x=\frac{0±\sqrt{640}}{2\times 8}$$

Take the square root of 640.

$$x=\frac{0±8\sqrt{10}}{2\times 8}$$

Multiply 2 times 8.

$$x=\frac{0±8\sqrt{10}}{16}$$

Now solve the equation x=\frac{0±8\sqrt{10}}{16} when ± is plus.

$$x=\frac{\sqrt{10}}{2}$$

Now solve the equation x=\frac{0±8\sqrt{10}}{16} when ± is minus.

$$x=-\frac{\sqrt{10}}{2}$$

The equation is now solved.

$$x=\frac{\sqrt{10}}{2} x=-\frac{\sqrt{10}}{2}$$