# How do you solve # x^2-2x-4=0# by completing the square?

##### 2 Answers

Mar 3, 2018

#### Explanation:

Add 1 to both sides,

Mar 3, 2018

#### Explanation:

#"using the method of "color(blue)"completing the square"#

#• " the coefficient of the "x^2" term must be 1 which it is"#

#• " add/subtract "(1/2"coefficient of x-term")^2" to"#

#x^2-2x#

#rArrx^2+2(-1)xcolor(red)(+1)color(red)(-1)-4=0#

#rArr(x-1)^2-5=0larrcolor(blue)"add 5 to both sides"#

#rArr(x-1)^2=5#

#color(blue)"Take square root of both sides"#

#rArrx-1=+-sqrt5larrcolor(blue)"note plus or minus"#

#"add 1 to both sides"#

#rArrx=1+-sqrt5larrcolor(red)"exact solutions"#