计算: ( 2 - 3 ) ( 2 + 3 ) + tan 60 ° - ( π - 2 3 ) 0
计算: (1);(2).
计算: (1);(2)(-6)×5×; (3)(-4)×7×(-1)×(-0.25);(4)
计算: (1)(2) (3)
计算: (1)(2) (3)(4)