I have divided everything by the (A-B).
(1+1)*(1-1) = 1*(1-1)
(1+1)*(1-1)/(1-1) = 1*(1-1)/(1-1)
the (1-1)/(1-1) cancel each other out (even though 0/0 doesn't ACTUALLY cancel each other out, but algebraically it makes sense because we're PURPOSELY ignoring the "if zero is the denominator, it doesn't work").
So we're left with (1+1) = 1
[And dividing by zero = +infinity and -infinity. Depends if you're going from the positive side or the negative side.]
(1+1)*(1-1) = 1*(1-1)
(1+1)*(1-1)/(1-1) = 1*(1-1)/(1-1)
the (1-1)/(1-1) cancel each other out (even though 0/0 doesn't ACTUALLY cancel each other out, but algebraically it makes sense because we're PURPOSELY ignoring the "if zero is the denominator, it doesn't work").
So we're left with (1+1) = 1
[And dividing by zero = +infinity and -infinity. Depends if you're going from the positive side or the negative side.]