1234567892−2⋅123456789⋅123456787+1234567872 the answer is not 0
a2 - 2ab + b2 = (a - b)2
So....
1234567892 - 2(123456789)(123456787) + 1234567872 = (123456789 - 123456787)2
And....
(123456789 - 123456787)2 = ( 2 )2 = 4
