### Home > CCA > Chapter 10 > Lesson 10.2.5 > Problem10-81

10-81.

Use square roots to find both solutions to each equation.

1.  $x^2−81=0$

Add $81$ to both sides.

Square root both sides.

This equation has $x^2$, so you should be looking for two possible solutions.

$x=\pm9$

1.  $x^2−37=0$

Use the same method as part (a). Is $37$ a perfect square?

$x=\pm \sqrt{37}$

1.  $x^2+49=0$

Use the same method as parts (a) and (b).

$x=\pm \sqrt{-49}$

1.  $2x^2+10=0$

One method would be to start by dividing the equation by $2$.

$x=\pm \sqrt{-5}$