Question

tìm x biết x^2 + x -2 = 0

Answer 1

x²+x-2=0

x²-x+2x-2=0

x.(x-1)+2.(x-1)=0

(x-1)(x+2)=0

=>x-1=0 hoặc x+2=0

x=1 hoặc x=-2

Answer 2

\(x^2+x-2=0\)

\(\Leftrightarrow x.\left(x+1\right)-2=0\)

\(\Leftrightarrow x.\left(x+1\right)=2\)

\(\Leftrightarrow x.\left(x+1\right)=1.2\)

                                      Vậy x = 1.