### Home > CAAC > Chapter 12 > Lesson 12.4.3 > Problem12-91

12-91.

Solve the quadratics below by completing the square. Leave your solutions in exact form.

1. $x^2−6x−12=0$

Add $21$ to both sides.

Perfect square form: $(x−3)^2=21$

$\textit{x}=3\pm \sqrt{21}$

1. $x^2−3=4x$

Change the quadratic into standard form before trying to change it to perfect square form.

Perfect square form: $(x−2)^2=7$