Solve (x+3)(x-3)=5

$$( x + 3 ) ( x - 3 ) = 5$$

Solve for x

$$x=\sqrt{14}\approx 3.741657387$$

$$x=-\sqrt{14}\approx -3.741657387$$

Steps by Finding Square Root

Consider \left(x+3\right)\left(x-3\right). Multiplication can be transformed into difference of squares using the rule: \left(a-b\right)\left(a+b\right)=a^{2}-b^{2}. Square 3.

$$x^{2}-9=5$$

Add 9 to both sides.

$$x^{2}=5+9$$

Add 5 and 9 to get 14.

$$x^{2}=14$$

Take the square root of both sides of the equation.

$$x=\sqrt{14} x=-\sqrt{14}$$

Steps Using the Quadratic Formula

Consider \left(x+3\right)\left(x-3\right). Multiplication can be transformed into difference of squares using the rule: \left(a-b\right)\left(a+b\right)=a^{2}-b^{2}. Square 3.

$$x^{2}-9=5$$

Subtract 5 from both sides.

$$x^{2}-9-5=0$$

Subtract 5 from -9 to get -14.

$$x^{2}-14=0$$

This equation is in standard form: ax^{2}+bx+c=0. Substitute 1 for a, 0 for b, and -14 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.

$$x=\frac{0±\sqrt{0^{2}-4\left(-14\right)}}{2}$$

Square 0.

$$x=\frac{0±\sqrt{-4\left(-14\right)}}{2}$$

Multiply -4 times -14.

$$x=\frac{0±\sqrt{56}}{2}$$

Take the square root of 56.

$$x=\frac{0±2\sqrt{14}}{2}$$

Now solve the equation x=\frac{0±2\sqrt{14}}{2} when ± is plus.

$$x=\sqrt{14}$$

Now solve the equation x=\frac{0±2\sqrt{14}}{2} when ± is minus.

$$x=-\sqrt{14}$$

The equation is now solved.

$$x=\sqrt{14} x=-\sqrt{14}$$