Solve y^2=0.49

$$y ^ { 2 } = 0.49$$

Solve for y

$$y=0.7$$

$$y=-0.7$$

Steps Using Difference of Squares

Subtract 0.49 from both sides.

$$y^{2}-0.49=0$$

Consider y^{2}-0.49. Rewrite y^{2}-0.49 as y^{2}-\left(\frac{7}{10}\right)^{2}. The difference of squares can be factored using the rule: a^{2}-b^{2}=\left(a-b\right)\left(a+b\right).

$$\left(y-\frac{7}{10}\right)\left(y+\frac{7}{10}\right)=0$$

To find equation solutions, solve y-\frac{7}{10}=0 and y+\frac{7}{10}=0.

$$y=\frac{7}{10} y=-\frac{7}{10}$$

Steps by Finding Square Root

Take the square root of both sides of the equation.

$$y=\frac{7}{10} y=-\frac{7}{10}$$

Steps Using the Quadratic Formula

Subtract 0.49 from both sides.

$$y^{2}-0.49=0$$

This equation is in standard form: ax^{2}+bx+c=0. Substitute 1 for a, 0 for b, and -0.49 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.

$$y=\frac{0±\sqrt{0^{2}-4\left(-0.49\right)}}{2}$$

Square 0.

$$y=\frac{0±\sqrt{-4\left(-0.49\right)}}{2}$$

Multiply -4 times -0.49.

$$y=\frac{0±\sqrt{1.96}}{2}$$

Take the square root of 1.96.

$$y=\frac{0±\frac{7}{5}}{2}$$

Now solve the equation y=\frac{0±\frac{7}{5}}{2} when ± is plus.

$$y=\frac{7}{10}$$

Now solve the equation y=\frac{0±\frac{7}{5}}{2} when ± is minus.

$$y=-\frac{7}{10}$$

The equation is now solved.

$$y=\frac{7}{10} y=-\frac{7}{10}$$