Solve 4x*x=100

$$4x \times x=100$$

Solve for x

$$x=5$$

$$x=-5$$

Steps by Finding Square Root

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

$$4x^{2}=100$$

Divide both sides by 4.

$$x^{2}=\frac{100}{4}$$

Divide 100 by 4 to get 25.

$$x^{2}=25$$

Take the square root of both sides of the equation.

$$x=5 x=-5$$

Steps Using the Quadratic Formula

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

$$4x^{2}=100$$

Subtract 100 from both sides.

$$4x^{2}-100=0$$

This equation is in standard form: ax^{2}+bx+c=0. Substitute 4 for a, 0 for b, and -100 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.

$$x=\frac{0±\sqrt{0^{2}-4\times 4\left(-100\right)}}{2\times 4}$$

Square 0.

$$x=\frac{0±\sqrt{-4\times 4\left(-100\right)}}{2\times 4}$$

Multiply -4 times 4.

$$x=\frac{0±\sqrt{-16\left(-100\right)}}{2\times 4}$$

Multiply -16 times -100.

$$x=\frac{0±\sqrt{1600}}{2\times 4}$$

Take the square root of 1600.

$$x=\frac{0±40}{2\times 4}$$

Multiply 2 times 4.

$$x=\frac{0±40}{8}$$

Now solve the equation x=\frac{0±40}{8} when ± is plus. Divide 40 by 8.

$$x=5$$

Now solve the equation x=\frac{0±40}{8} when ± is minus. Divide -40 by 8.

$$x=-5$$

The equation is now solved.

$$x=5 x=-5$$