Solve x*x-1=56

$$x \times x-1=56$$

Solve for x

$$x=\sqrt{57}\approx 7.549834435$$

$$x=-\sqrt{57}\approx -7.549834435$$

Steps by Finding Square Root

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

$$x^{2}-1=56$$

Add 1 to both sides.

$$x^{2}=56+1$$

Add 56 and 1 to get 57.

$$x^{2}=57$$

Take the square root of both sides of the equation.

$$x=\sqrt{57} x=-\sqrt{57}$$

Steps Using the Quadratic Formula

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

$$x^{2}-1=56$$

Subtract 56 from both sides.

$$x^{2}-1-56=0$$

Subtract 56 from -1 to get -57.

$$x^{2}-57=0$$

This equation is in standard form: ax^{2}+bx+c=0. Substitute 1 for a, 0 for b, and -57 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.

$$x=\frac{0±\sqrt{0^{2}-4\left(-57\right)}}{2}$$

Square 0.

$$x=\frac{0±\sqrt{-4\left(-57\right)}}{2}$$

Multiply -4 times -57.

$$x=\frac{0±\sqrt{228}}{2}$$

Take the square root of 228.

$$x=\frac{0±2\sqrt{57}}{2}$$

Now solve the equation x=\frac{0±2\sqrt{57}}{2} when ± is plus.

$$x=\sqrt{57}$$

Now solve the equation x=\frac{0±2\sqrt{57}}{2} when ± is minus.

$$x=-\sqrt{57}$$

The equation is now solved.

$$x=\sqrt{57} x=-\sqrt{57}$$