How do you solve using the completing the square method x^2-12x+20=0?

1 Answer
May 29, 2018

x=2" or "x=10

Explanation:

"subtract 20 from both sides"

x^2-12x=-20

• " add "(1/2"coefficient of the x-term")^2" to both sides"

x^2+2(-6)x color(red)(+36)=-20color(red)(+36)

(x-6)^2=16

color(blue)"take the square root of both sides"

sqrt((x-6)^2)=+-sqrt16larrcolor(blue)"note plus or minus"

x-6=+-4

"add 6 to both sides"

x=6+-4

x=6-4=2" or "x=6+4=10