Question

12345*12346-12344*12343 简便运算

Answer 1

设12345为A，12343为B
原式=A(A+1)-B(B+1)
=A^2-B^2+A-B
=(A+B)(A-B)+A-B
=(A+B+1)(A-B)
=(12345+12343+1)(12345-12343)
=24689*2
=49378