Question

Tính nhanh: LƯU Ý tất cả số dưới đây đều là phân số

1,1/8 x 2/5 + 3/5 + 1/8

2,( -1)/15 x 2/5 + (-5)/3 x (-1)/13

3,4/9 : 11/6 + 5/9 x 6/11

4,5/19 x 7/13 + 7/19 x 8/13 - 3 x 7/19

5, 2/7 x 4/23 - 2/7 x 27/23 + 2/7

6,3/8 x 3/7 +3/8 x 4/7 + 11/8

7,-5/27 : 6/11 - 16/11 x 5/27 - 5/27

8, 5/16 x 7/8 - 5/16 x 1/8 + 10/8 :16/5

9,1/3 x 39/17 - 129/3 x 1/17

10,5/2 : 23/3 - 3/2 x 7/23

Answer 1

2: \(=\dfrac{-2}{75}+\dfrac{5}{39}=\dfrac{33}{325}\)

3: \(=\dfrac{6}{11}\left(\dfrac{4}{9}+\dfrac{5}{9}\right)=\dfrac{6}{11}\)

4: \(=\dfrac{7}{19}\left(\dfrac{5}{13}+\dfrac{8}{13}-1\right)=-2\cdot\dfrac{7}{19}=-\dfrac{14}{19}\)

5: \(=\dfrac{2}{7}\left(\dfrac{4}{23}-\dfrac{27}{23}+1\right)=0\)

6: \(=\dfrac{3}{8}\left(\dfrac{3}{7}+\dfrac{4}{7}\right)+\dfrac{11}{8}=\dfrac{3}{8}+\dfrac{11}{8}=\dfrac{14}{8}=\dfrac{7}{4}\)