计算(1)(+11)+(―12.1)(2)(-2.4)+(+2.4)(3)(+4)―(―3)(4) 0―(―) (5)(―)―(+)(6) ―3―4+19―11 (7) ―+―
计算: (1). (2). (3). (4).
计算:(每小题4分,共8分.) (1)求的值:. (2)计算:;
(本题6分)计算: (1) (2)