Solve (1.2+x)*(1.2-x)=1.08

$$( 1.2 + x ) \times ( 1.2 - x ) = 1.08$$

Solve for x

$$x=0.6$$

$$x=-0.6$$

Steps by Finding Square Root

Consider \left(1.2+x\right)\left(1.2-x\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 1.2.

$$1.44-x^{2}=1.08$$

Subtract 1.44 from both sides.

$$-x^{2}=1.08-1.44$$

Subtract 1.44 from 1.08 to get -0.36.

$$-x^{2}=-0.36$$

Divide both sides by -1.

$$x^{2}=\frac{-0.36}{-1}$$

Expand \frac{-0.36}{-1} by multiplying both numerator and the denominator by 100.

$$x^{2}=\frac{-36}{-100}$$

Reduce the fraction \frac{-36}{-100} to lowest terms by extracting and canceling out -4.

$$x^{2}=\frac{9}{25}$$

Take the square root of both sides of the equation.

$$x=\frac{3}{5} x=-\frac{3}{5}$$

Steps Using the Quadratic Formula

Consider \left(1.2+x\right)\left(1.2-x\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 1.2.

$$1.44-x^{2}=1.08$$

Subtract 1.08 from both sides.

$$1.44-x^{2}-1.08=0$$

Subtract 1.08 from 1.44 to get 0.36.

$$0.36-x^{2}=0$$

Quadratic equations like this one, with an x^{2} term but no x term, can still be solved using the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}, once they are put in standard form: ax^{2}+bx+c=0.

$$-x^{2}+\frac{9}{25}=0$$

This equation is in standard form: ax^{2}+bx+c=0. Substitute -1 for a, 0 for b, and \frac{9}{25} for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.

$$x=\frac{0±\sqrt{0^{2}-4\left(-1\right)\times \frac{9}{25}}}{2\left(-1\right)}$$

Square 0.

$$x=\frac{0±\sqrt{-4\left(-1\right)\times \frac{9}{25}}}{2\left(-1\right)}$$

Multiply -4 times -1.

$$x=\frac{0±\sqrt{4\times \frac{9}{25}}}{2\left(-1\right)}$$

Multiply 4 times \frac{9}{25}.

$$x=\frac{0±\sqrt{\frac{36}{25}}}{2\left(-1\right)}$$

Take the square root of \frac{36}{25}.

$$x=\frac{0±\frac{6}{5}}{2\left(-1\right)}$$

Multiply 2 times -1.

$$x=\frac{0±\frac{6}{5}}{-2}$$

Now solve the equation x=\frac{0±\frac{6}{5}}{-2} when ± is plus.

$$x=-\frac{3}{5}$$

Now solve the equation x=\frac{0±\frac{6}{5}}{-2} when ± is minus.

$$x=\frac{3}{5}$$

The equation is now solved.

$$x=-\frac{3}{5} x=\frac{3}{5}$$