How do you solve using the completing the square method #x^2-2x-13 = 0#?

1 Answer
Jan 9, 2018

#x=1+-sqrt14#

Explanation:

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

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

#x^2-2x-13=0#

#rArrx^2-2x=13#

#rArrx^2+2(-1)xcolor(red)(+1)=13color(red)(+1)#

#rArr(x-1)^2=14#

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

#x-1=+-sqrt14larrcolor(blue)"note plus or minus"#

#rArrx=1+-sqrt14#