a*b=0 => a=0 v
b=0
a^2=b^2 => a=b v
a=-b
a*b=a*c => a=0 v
b=c
a*b=a => a=0 v
b=1
a/b=0 => a=0 en
a/b=c => a=BC en

a/b=c/d => ad=bc

a/b=a/c => a=0 v
b=c
a/b=c/b => a=c
(a+b)^2=a^2+2ab+
b^2
(a-b)^2=a^2-2ab+
b^2
(a+b)(a-B)= a^2+
b^2