a,3/2.7/3+14/3.1/2 b,1/9.145-13/3.2/145+2/145 c,(-31/12):15/7-1/18:15/7+20/9:15/7 d,7/80;(-7/3)-2/9:(8-8/3)-5/24.(-10/3+38/15)

0 bình luận về “a,3/2.7/3+14/3.1/2 b,1/9.145-13/3.2/145+2/145 c,(-31/12):15/7-1/18:15/7+20/9:15/7 d,7/80;(-7/3)-2/9:(8-8/3)-5/24.(-10/3+38/15)”

1. Đáp án:a)35/6,       b)4193/261           c)-7/36               d)7/80

    

   Giải thích các bước giải:

   a)3/2.7/3+14/3.1/2

   =7/2+7/3

   =21/6+14/6

   =35/6

   b)1/9.145-13/3.2/145+2/145

   =145/9-2/145(13/3-1)

   =145/9-2/145.10/3

   =145/9-4/87

   =4205/261-12/261

   =4193/261

   c)(-31/12):15/7-1/18:15/7+20/9:15/7

   =((-31/12)-1/18+20/9):15/7

   =((-93/36-2/36+80/36).7/15

   =(-5/12).7/15

   =-7/36

   d),7/80;(-7/3)-2/9:(8-8/3)-5/24.(-10/3+38/15)

   =7/80.(-3/7)-2/9:(24/3-8/3)-5/24.(-50/15+38/15)

   =(-3/80)-2/9:16/3-5/24.4/5

   =(-3/80)-2/9.3/16-(-1/6)

   =(-3/80)-1/24-(-1/6)

   =(-9/240)-10/240-(-40/240)

   =7/80

    

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2. Đáp án:

    

   Giải thích các bước giải:

    a,3/2.7/3+14/3.1/2=3/2.7/3+7/3.2.1/2=(3/2+2.1/2).7/3=(3/2+1).7/3=5/2.7/3=35/6

   b,1/9.145-13/3.2/145+2/145=1\9.145-2/145.(13/3+1)=145/9-2/145.16/3=145/9-32/435=20929/1305

   c,(-31/12):15/7-1/18:15/7+20/9:15/7=(-31/12).7/15-1/18.7/15+20/9.7/15=[(-31/12)-1/18+20/9].7/15=-5/12.7/15=-7/36

   d,7/80:(-7/3)-2/9:(8-8/3)-5/24.(-10/3+38/15)=7/80.(-3/7)-2/9:(16/3)-5/24.(-4/5)=7/80.(-3/7)-2/9.3/16-5/24.(-4/5)=-3/80-1/24-(-1/6)=7/80

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