1/5 + 3/5 2/3 . 2/7 -2/3 . 3/7 +8/7 . 2/3 -3/5+7/13+-2/5+ -23/25 + 6/13 (1/3+3/4 -13/12):(12/23+123/234+1234/2345)

0 bình luận về “1/5 + 3/5 2/3 . 2/7 -2/3 . 3/7 +8/7 . 2/3 -3/5+7/13+-2/5+ -23/25 + 6/13 (1/3+3/4 -13/12):(12/23+123/234+1234/2345)”

1. a, $\frac{1}{5}$ + $\frac{3}{5}$ 

   = $\frac{1+3}{5}$ = $\frac{4}{5}$ 

   b. $\frac{2}{3}$ . $\frac{2}{7}$ – $\frac{2}{3}$ . $\frac{3}{7}$ + $\frac{8}{7}$ . $\frac{2}{3}$ 

   = $\frac{2}{3}$ . ($\frac{2}{7}$ – $\frac{3}{7}$+ $\frac{8}{7}$)

   = $\frac{2}{3}$ . 1 = $\frac{2}{3}$

   c. $\frac{-3}{5}$ + $\frac{7}{13}$ + $\frac{-2}{5}$+ $\frac{-23}{25}$ + $\frac{6}{13}$

   = ($\frac{-3}{5}$ + $\frac{-2}{5}$) + ($\frac{7}{13}$+ $\frac{6}{13}$)+ $\frac{-23}{25}$

   = -1 + 1 + $\frac{-23}{25}$

   = 0 + $\frac{-23}{25}$

   = $\frac{-23}{25}$

   d. (1/3+3/4 -13/12):(12/23+123/234+1234/2345)

   = (4/12 + 9/12 – 13/12) : (12/23+123/234+1234/2345)

   = 0: (12/23+123/234+1234/2345)

   = 0

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2. a) 1/5 + 3/5 = 4/5

   b) 2/3 . 2/7 -2/3 . 3/7 +8/7 . 2/3

    = 4/21 – 6/21 + 16/21 = 14/21

   c) -3/5+7/13+-2/5+ -23/25 + 6/13

   = -5/5 + 13/13 – 23/25

   = -23/25

   d) (1/3+3/4 -13/12):(12/23+123/234+1234/2345)

   = (4/12+9/12-13/12) : (12/23+123/234+1234/2345)

   = 0 : (12/23+123/234+1234/2345) = 0

    

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