Question

6.Tính

a, 2/5 + 3/4

7/12 - 2/7 + 1/12

12/17-5/17-4/17

b, 675,39 +342,14

563,87 +403,13 -328,35

mn làm cả cách làm đầy đủ nha.Rồi mình sẽ tick cho nhoa.Cảm ơn

ví dụ 7/2 có nghĩa là 7 phần 12 nha

Answer 1

a,\(\frac{2}{5}+\frac{3}{4}=\frac{8+15}{20}=\frac{23}{20}\)

\(\frac{7}{12}-\frac{2}{7}+\frac{1}{12}=(\frac{7}{12}+\frac{1}{12})-\frac{2}{7}\)

\(=\frac{2}{3}-\frac{2}{7}=\frac{14-6}{21}=\frac{8}{21}\)

\(\frac{12}{17}-\frac{5}{17}-\frac{4}{17}=\frac{7}{17}-\frac{4}{17}=\frac{3}{17}\)

b,\(675,39+342,14=1017,53\)

\(563,87+403,13-328,35=638,65\)

Answer 2

2/5+3/4=23/20

7/12-2/7+1/12=8/21

12/17-5/17-4/173/17

675,39+342,14=1017,53

563,87+403,13-328,35=638,65