1+1=2-1

=3-2

=4-3

=5-4

=...-...=2ehehe

-Đáp án : 1 + 1 =2

Ví dụ : 1 cái bút + 1 cái bút = 2 cái bút

-Đáp án : 1 + 1 =3

Ví dụ : Bố + mẹ = bố , mẹ và con

-Đáp án: 1 + 1 = 1

Ví dụ : 1 chiếc tất + 1 chiếc tất = 1 đôi tất.

Vân vân và mây mây
 

=7986575756465353578708806867463524243445568679988087685746353524132435645675 OK

99999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999

=>(x-2)(2x+3-x-1)=0

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

=>x=2 hoặc x=-2