Solve x^2/4^2=39/1.3

$$\frac { x ^ { 2 } } { 4 ^ { 2 } } = \frac { 39 } { 1.3 }$$

Solve for x

$$x=4\sqrt{30}\approx 21.9089023$$

$$x=-4\sqrt{30}\approx -21.9089023$$

Steps by Finding Square Root

Calculate 4 to the power of 2 and get 16.

$$\frac{x^{2}}{16}=\frac{39}{1.3}$$

Expand \frac{39}{1.3} by multiplying both numerator and the denominator by 10.

$$\frac{x^{2}}{16}=\frac{390}{13}$$

Divide 390 by 13 to get 30.

$$\frac{x^{2}}{16}=30$$

Multiply both sides by 16.

$$x^{2}=30\times 16$$

Multiply 30 and 16 to get 480.

$$x^{2}=480$$

Take the square root of both sides of the equation.

$$x=4\sqrt{30} x=-4\sqrt{30}$$

Steps Using the Quadratic Formula

Calculate 4 to the power of 2 and get 16.

$$\frac{x^{2}}{16}=\frac{39}{1.3}$$

Expand \frac{39}{1.3} by multiplying both numerator and the denominator by 10.

$$\frac{x^{2}}{16}=\frac{390}{13}$$

Divide 390 by 13 to get 30.

$$\frac{x^{2}}{16}=30$$

Subtract 30 from both sides.

$$\frac{x^{2}}{16}-30=0$$

Multiply both sides of the equation by 16.

$$x^{2}-480=0$$

This equation is in standard form: ax^{2}+bx+c=0. Substitute 1 for a, 0 for b, and -480 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.

$$x=\frac{0±\sqrt{0^{2}-4\left(-480\right)}}{2}$$

Square 0.

$$x=\frac{0±\sqrt{-4\left(-480\right)}}{2}$$

Multiply -4 times -480.

$$x=\frac{0±\sqrt{1920}}{2}$$

Take the square root of 1920.

$$x=\frac{0±8\sqrt{30}}{2}$$

Now solve the equation x=\frac{0±8\sqrt{30}}{2} when ± is plus.

$$x=4\sqrt{30}$$

Now solve the equation x=\frac{0±8\sqrt{30}}{2} when ± is minus.

$$x=-4\sqrt{30}$$

The equation is now solved.

$$x=4\sqrt{30} x=-4\sqrt{30}$$