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Answer 1 · 2016-04-22T16:25:52

#x=2, -1#

#x^2-x-2=0#

#x^2-x-2+2=0+2#

#x^2-x=2#

Add the square of -1/2 (the coefficient of the #-x# divided by 2) to both sides. Remember, the standard form is #x^2 + 2ax + a^2#
#x^2-x+1/4=2+1/4#

Factor the left side of the equation
#(x-1/2)(x-1/2)=2 1/4#
#(x-1/2)^2 =2 1/4#

#sqrt((x-1/2)^2) =sqrt(2 1/4)#

#(x-1/2)=+-1 1/2#

#x=1/2+-1 1/2=2,-1#