How do you solve using the completing the square method # x^2+8x9=0#?
1 Answer
Mar 18, 2016
Completing the square is designed to give you a perfect square trinomial on the left of an equation.
Explanation:

Get any constants on the right side.
#x^2+8x=9# 
Add
#(b/2)^2=(8/2)^2# to both sides
#x^2+8x+16=9+16# 
Factor the left.
#(x+4)^2=25# 
Square root both sides.
#(x+4)=+5# 
#x={54,54} = {1,9}#