简便计算:123的平方—124×122=?

问题描述:

简便计算:123的平方—124×122=?

123*123-(123+1)*122=123*(123-122)+122=245

=124*123-123-124*122
=124*(123-122)-123
=124-123=1

原式=123²-(123+1)×(123-1)
=123²²-(123²-1²)
=123²-123²+1
=1

123^2-(123+1)(123-1)
=123^2-(123^2-1)
=123^2-123^2+1=1