About Completing the Square:

We can solve any quadratic equation using a process known as completing the square. This process creates a perfect square trinomial on one side of the equation, with a constant on the other. We then factor using our special factoring formulas and solve the equation using the square root property.


Test Objectives
  • Demonstrate the ability to form a perfect square trinomial by completing the square
  • Demonstrate the ability to factor a perfect square trinomial into the square of a binomial
  • Demonstrate the ability to solve a quadratic equation of the form: (x + a)2 = k
Completing the Square Practice Test:

#1:

Instructions: Solve each equation by completing the square.

a) $$4p^2 - 16=6p$$


#2:

Instructions: Solve each equation by completing the square.

a) $$-k^2-15k=14$$


#3:

Instructions: Solve each equation by completing the square.

a) $$8m^2 + 9m - 72=5m$$


#4:

Instructions: Solve each equation by completing the square.

a) $$19a=-4a^2 + 93$$


#5:

Instructions: Solve each equation by completing the square.

a) $$7p^2 + 21p=-9$$


Written Solutions:

#1:

Solutions:

a) $$p=\frac{\pm\sqrt{73}+ 3}{4}$$


#2:

Solutions:

a) $$k=-1$$ or $$k=-14$$


#3:

Solutions:

a) $$m=\frac{\pm \sqrt{145}- 1}{4}$$


#4:

Solutions:

a) $$a=3$$ or $$a=-\frac{31}{4}$$


#5:

Solutions:

a) $$p=\frac{\pm 3\sqrt{21}- 21}{14}$$