Solve D^2=243

$$D ^ { 2 } = 243$$

Solve for D

$$D=9\sqrt{3}\approx 15.588457268$$

$$D=-9\sqrt{3}\approx -15.588457268$$

Steps by Finding Square Root

Take the square root of both sides of the equation.

$$D=9\sqrt{3} D=-9\sqrt{3}$$

Steps Using the Quadratic Formula

Subtract 243 from both sides.

$$D^{2}-243=0$$

This equation is in standard form: ax^{2}+bx+c=0. Substitute 1 for a, 0 for b, and -243 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.

$$D=\frac{0±\sqrt{0^{2}-4\left(-243\right)}}{2}$$

Square 0.

$$D=\frac{0±\sqrt{-4\left(-243\right)}}{2}$$

Multiply -4 times -243.

$$D=\frac{0±\sqrt{972}}{2}$$

Take the square root of 972.

$$D=\frac{0±18\sqrt{3}}{2}$$

Now solve the equation D=\frac{0±18\sqrt{3}}{2} when ± is plus.

$$D=9\sqrt{3}$$

Now solve the equation D=\frac{0±18\sqrt{3}}{2} when ± is minus.

$$D=-9\sqrt{3}$$

The equation is now solved.

$$D=9\sqrt{3} D=-9\sqrt{3}$$