(1) | - 5 | - ( - 3 ) 2 - ( 7 ) 0
(2) ( a - b ) 2 - a ( a - 2 b )
计算: (1)(2) (3)
计算: (1)(2) (3)(4)
计算: (+1)+(-2)+(+3)+(-4)+…+(+99)+(-100)
计算:
计算: (1) (2)