有理数计算题
(1)(+11)+(-7)+(+10)+(-3)+(-11) (2)-(-2.4)-(+3.7)+(-4.6)-(-5.7) (3)1-3+5-7+9-11+...+97-99 (4)丨-2/5丨-(3.5)+丨-1-2/3丨
(1)(+11)+(-7)+(+10)+(-3)+(-11) =11|-7+10-3-11 =0 (2)-(-2.4)-(+3.7)+(-4.6)-(-5.7) =2.4-3.7-4.6+5.7 =_0.2
(1)(+11)+(-7)+(+10)+(-3)+(-11) =(+4) +(+10)+(-3)+(-11) =(+14)+(-3)+(-11) =(+11)+(-11) =0 (2)-(-2.4)-(+3.7)+(-4.6)-(-5.7) =(+2.4)-(+3.7)+(-4.6)-(-5.7) =(-1.3)+(-4.6)-(-5.7) =(-5.9)-(-5.7) =(-5.9)+(+5.7) =-0.2 (3)1-3+5-7+9-11+...+97-99 =(1-3)+(5-7)+(9-11)+.....+(97-99) =-2*[(99+1)/2/2] =-2*25 =-50 (4)丨-2/5丨-(3.5)+丨-1-2/3丨 =(2/5)-(7/2)+(5/3) =(-31/10)+(5/3) =-43/30
答:1.1/1+2 + 1/1+2+3 + 1/1+2+3+4 +……+ 1/1+2+3+4+……+100 =2[(1/2-1/3)+(1/3-1/4)+(1/4-...详情>>
答:详情>>