a/3/4x 3,8 +6,2 x1và 1/2 b/ 2/11 +7/8 +9/11+1/8 c/ 14/15 x3/7 +1/3 d/ 2- 3/5 :3/4

1 bình luận về “a/3/4x 3,8 +6,2 x1và 1/2 b/ 2/11 +7/8 +9/11+1/8 c/ 14/15 x3/7 +1/3 d/ 2- 3/5 :3/4”

1. a) 3/4 xx 3,8 + 6,2 xx 1 1/2

   = 3/4 xx 19/5 + 31/5 xx 3/2

   = 57/20 + 93/10

   = 57/20 + 186/20

   = 243/10

   = 24,3

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   b) 2/11 +7/8 +9/11+1/8

   = 2/11 +9/11+1/8+7/8

   = 11/11+8/8

   = 1+1

   = 2

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   c) 14/15 xx3/7 +1/3

   = (14xx3)/(15xx7) +1/3

   = (7xx2xx3)/(3xx5xx7) +1/3

   = 2/5 +1/3

   = 6/15 + 5/15

   = 11/15

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   d) 2- 3/5 :3/4

   = 2- 3/5 xx4/3

   = 2- (3xx4)/(5xx3)

   = 2- 4/5

   = 10/5 – 4/5

   = 6/5

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