Question

2.5有理数加法减法混合运算 计算：（1）7+4-5 （2）-5-3-9+7+三分之二 （3）-10-12+36-23

（4）-二分之三-十二分之五+二分之五-十二分之七 （5）16-8-l-3l+l+8l-l-12l-(+5) (6)-26+43-24+13-46 (7) -6-8-2+3.54-4.72+16.46-5.28 (8) - 二分之一 -六分之一+四分之一 - 三分之二 （9）-2.1-3.2+2.4+4.3（10）19+15-3-7 （11）-23+72-31+47 （12）-1.6-3又五分之一+l-1.8l (13)1-4-2-l-5l (14)-2又五分之一 - 1又三分之一 - 2又六分之一+4又五分之一 （要步骤哦，跪求！！！）

Answer 1

7 + 4 - 5 = 11 - 5 = 6 -5 - 3 - 9 + 7 + 2/3 = (-5 - 3 - 9 + 7) + 2/3 = -10 + 2/3 = -9又3分之1 -10 - 12 + 36 - 23 = -22 + 36 - 23 = 14 - 23 = -9 -3/2 - 5/12 + 5/2 - 7/12 = (-3/2 + 5/2) - (5/12 + 7/12) = 1 - 1 = 0 16 - 8 -｜-3｜+ ｜+8｜- ｜-12｜- (+5) = 16 - 8 - 3 + 8 - 12 - 5 = (16 - 3 - 12) - 5 - (8 - 8) = 1 - 5 - 0 = -4 -26 + 43 - 24 + 13 - 46 = (-26 - 24) + (43 + 13 - 46) = -50 + 10 = -40 -6 - 8 -2 + 3.54 - 4.72 + 16.46 - 5.28 = (-6 - 8 - 2) + (3.54 + 16.46) - (4.72 + 5.28) = -16 + 20 - 10 = 4 - 10 = -6 -1/2 - 1/6 + 1/4 - 2/3 = (-1/2 + 1/4) - (1/6 + 2/3) = -1/4 - 5/6 = -7/12 -2.1 - 3.2 + 2.4 + 4.3 = (-2.1 + 2.4) + (-3.2 + 4.3) = 0.3 + 1.1 = 1.4 19 + 15 - 3 - 7 = (19 + 15) - (3 + 7) = 34 - 10 = 24 -23 + 72 - 31 + 47 = 49 - 31 + 47 = 18 + 47 = 65 -1.6 - 3又5分之1 + ｜-1.8｜ = -1.6 - 3.2 + 1.8 = -1.6 - (3.2 - 1.8) = -1.6 - 1.4 = - 3 1 - 4 - 2 - ｜-5｜ = 1 - 4 - 2 - 5 = -3 - 2 - 5 = -10 -2又5分之1 - 1又3分之1 - 2又6分之1 + 4又5分之1 = （-2又5分之1 + 4又5分之1）- （1又3分之1 + 2又6分之1） = 2 - 3.5 = -1.5

Answer 2

1.(-1/3)-(-1/2)+3/4+(-2/3) %D%A=(-1/3-2/3)+(1/2+3/4)%D%A=-1+5/4%D%A=1/4%D%A%D¢.1.36-(-2.64+5.2)-0.2 %D%A=(1.36+2.64)-(5.2+0.2)%D%A%D%A=4-5.4%D%A=-1.4%D%A%D£.3又7/45+12又4/13-9又2/5+7又5/26 %D%A=(3又7/45-9又2/5)+(12又4/13+7又5/26)%D%A=-6又11/45+19又1/2%D%A=13又23/90%D%A%D%A 4. -0.5-（-3又1/4）+2.75-（+7又1/2)%D%A=-0.5+3.25+2.75-7.5%D%A=-2%D%A%D¥. 5/4+[-2又1/3-(1 又3/4-1又2/3)] %D%A= 5/4-2又1/3-1 又3/4+1又2/3 %D%A= (5/4-1又3/4)-(2又1/3-1又2/3)%D%A=-1/2-2/3%D%A=-1又1/6%D%A%D¦.-(-3.21)-(+2.47)-(-1.53)+(+1.29)%D%A=3.21-2.47+1.53+1.29%D%A=3.56