Solve x^2-18*+81=5

$${ x }^{ 2 } -18 \times +81=5$$

Solve for x

$$x=\sqrt{1463}\approx 38.249182998$$

$$x=-\sqrt{1463}\approx -38.249182998$$

Steps by Finding Square Root

Multiply 18 and 81 to get 1458.

$$x^{2}-1458=5$$

Add 1458 to both sides.

$$x^{2}=5+1458$$

Add 5 and 1458 to get 1463.

$$x^{2}=1463$$

Take the square root of both sides of the equation.

$$x=\sqrt{1463} x=-\sqrt{1463}$$

Steps Using the Quadratic Formula

Multiply 18 and 81 to get 1458.

$$x^{2}-1458=5$$

Subtract 5 from both sides.

$$x^{2}-1458-5=0$$

Subtract 5 from -1458 to get -1463.

$$x^{2}-1463=0$$

This equation is in standard form: ax^{2}+bx+c=0. Substitute 1 for a, 0 for b, and -1463 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.

$$x=\frac{0±\sqrt{0^{2}-4\left(-1463\right)}}{2}$$

Square 0.

$$x=\frac{0±\sqrt{-4\left(-1463\right)}}{2}$$

Multiply -4 times -1463.

$$x=\frac{0±\sqrt{5852}}{2}$$

Take the square root of 5852.

$$x=\frac{0±2\sqrt{1463}}{2}$$

Now solve the equation x=\frac{0±2\sqrt{1463}}{2} when ± is plus.

$$x=\sqrt{1463}$$

Now solve the equation x=\frac{0±2\sqrt{1463}}{2} when ± is minus.

$$x=-\sqrt{1463}$$

The equation is now solved.

$$x=\sqrt{1463} x=-\sqrt{1463}$$