Solve b^2=800-100

$$b ^ { 2 } = 800 - 100$$

Solve for b

$$b=10\sqrt{7}\approx 26.457513111$$

$$b=-10\sqrt{7}\approx -26.457513111$$

Steps by Finding Square Root

Subtract 100 from 800 to get 700.

$$b^{2}=700$$

Take the square root of both sides of the equation.

$$b=10\sqrt{7} b=-10\sqrt{7}$$

Steps Using the Quadratic Formula

Subtract 100 from 800 to get 700.

$$b^{2}=700$$

Subtract 700 from both sides.

$$b^{2}-700=0$$

This equation is in standard form: ax^{2}+bx+c=0. Substitute 1 for a, 0 for b, and -700 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.

$$b=\frac{0±\sqrt{0^{2}-4\left(-700\right)}}{2}$$

Square 0.

$$b=\frac{0±\sqrt{-4\left(-700\right)}}{2}$$

Multiply -4 times -700.

$$b=\frac{0±\sqrt{2800}}{2}$$

Take the square root of 2800.

$$b=\frac{0±20\sqrt{7}}{2}$$

Now solve the equation b=\frac{0±20\sqrt{7}}{2} when ± is plus.

$$b=10\sqrt{7}$$

Now solve the equation b=\frac{0±20\sqrt{7}}{2} when ± is minus.

$$b=-10\sqrt{7}$$

The equation is now solved.

$$b=10\sqrt{7} b=-10\sqrt{7}$$