\(=\dfrac{5}{12}-\dfrac{7}{32}\cdot\dfrac{16}{21}=\dfrac{5}{12}-\dfrac{1}{6}=\dfrac{5}{12}-\dfrac{2}{12}=\dfrac{1}{4}\)

\(\dfrac{5}{12}-\dfrac{7}{32}:\dfrac{21}{16}=\dfrac{5}{12}-\dfrac{7}{32}\times\dfrac{16}{21}=\dfrac{5}{12}-\dfrac{1}{6}=\dfrac{5}{12}-\dfrac{2}{12}=\dfrac{3}{12}=\dfrac{1}{4}\)

1/4

1/4 có rút gọn rồi nha 

nhưng cậu có thể giải thích là tại sao lại là \(\dfrac{1}{4}\) ko?

Ghi đầy đủ nha

bn có thể ghi rõ ràng đc ko?

a)\(-\dfrac{3}{7}+\dfrac{5}{13}+\dfrac{3}{7}\) 

=\(\left(-\dfrac{3}{7}+\dfrac{3}{7}\right)+\dfrac{5}{13}\) 

=\(0+\dfrac{5}{13}\) 

=\(\dfrac{5}{13}\)

a)\(=\dfrac{16}{13}-\dfrac{3}{15}+\dfrac{6}{13}=\dfrac{22}{13}-\dfrac{3}{15}=\dfrac{96}{65}\)

b)\(=\dfrac{21}{8}-\left(\dfrac{5}{10}+\dfrac{6}{10}\right)=\dfrac{21}{8}-\dfrac{11}{10}=\dfrac{61}{40}\)

c)\(=\dfrac{27}{10}-3-\dfrac{4}{7}--\dfrac{61}{70}\)

d)\(=\dfrac{576}{702}=\dfrac{4}{5}\)

e)\(=\left(\dfrac{20}{15}-\dfrac{12}{15}\right)\times\dfrac{25}{2}=\dfrac{8}{15}\times\dfrac{25}{2}=\dfrac{20}{3}\)

f)\(=\dfrac{24}{12}-\dfrac{4}{12}-\dfrac{6}{12}-\dfrac{2}{12}-\dfrac{3}{12}=\dfrac{9}{12}=\dfrac{3}{4}\)

d) \(=\dfrac{32}{45}x\dfrac{18}{16}=\dfrac{576}{720}=\dfrac{115}{114}\)

e) \(=\left(\dfrac{4}{3}-\dfrac{4}{5}\right)x\dfrac{25}{12}=\dfrac{8}{15}x\dfrac{25}{12}=\dfrac{200}{180}=\dfrac{10}{9}\)

f) \(=\dfrac{2}{1}-\dfrac{1}{3}-\dfrac{1}{2}-\dfrac{1}{6}-\dfrac{3}{12}=\dfrac{24}{12}-\dfrac{4}{12}-\dfrac{6}{12}-\dfrac{2}{12}-\dfrac{3}{12}\)

\(=\dfrac{20}{12}-\dfrac{4}{12}-\dfrac{3}{12}=\dfrac{16}{12}-\dfrac{3}{12}=\dfrac{13}{12}\)

1.\(\dfrac{8}{11}+\dfrac{8}{33}\times\dfrac{3}{4}=\dfrac{8}{11}+\dfrac{8\times3}{33\times4}=\dfrac{8\times12}{11\times12}+\dfrac{8\times3}{33\times4}=\dfrac{8\times15}{132}=\dfrac{120}{132}=\dfrac{10}{11}\)

2.\(\dfrac{7}{9}\times\dfrac{3}{14}:\dfrac{5}{8}=\dfrac{7}{9}\times\dfrac{3}{14}\times\dfrac{8}{5}=\dfrac{4}{15}\)

3.\(\dfrac{5}{12}-\dfrac{7}{32}:\dfrac{21}{16}=\dfrac{5}{12}-\dfrac{7}{32}\times\dfrac{16}{21}=\dfrac{5}{12}-\dfrac{1}{6}=\dfrac{5-2}{12}=\dfrac{3}{12}=\dfrac{1}{4}\)

`@V.Tr.V`

`8/11+8/33xx3/4=8/11+2/11=10/11`

`7/9xx3/14:5/8=7/9xx3/14xx8/5=[7xx3xx4xx2]/[3xx3xx7xx2xx5]=4/[3xx5]=4/15`

`5/12-7/32:21/16=5/12-7/32xx16/21=5/12-2/12=3/12=1/4`

8/11 + 8/33 x 3/4 = 8/11 + 2/11 = 10/11

7/9 x 3/14 : 5/8 = 1/6 : 5/8 = 4/15

5/12 - 7/32 : 21/16 = 5/12 - 1/6 = 1/4

\(\frac{5}{12}-\frac{7}{32}:\frac{21}{16}\)

=\(\frac{5}{12}-\frac{7}{32}.\frac{16}{21}\)

=\(\frac{5}{12}-\frac{1}{6}\)

=\(\frac{5}{12}-\frac{2}{12}\)

=\(\frac{1}{4}\)

1: Ta có: \(2155-\left(174+2155\right)+\left(-68+174\right)\)

\(=2155-174-2155-68+174\)

=-68

2) Ta có: \(-25\cdot72+25\cdot21-49\cdot25\)

\(=-25\cdot\left(72-21+49\right)\)

\(=-25\cdot100=-2500\)

8 x 2 = 16       8 x 4 = 32       8 x 7 = 56       8 x 5 = 40

16 : 8 = 2       32 : 8 = 4       56 : 8 = 7       40 : 8 = 5

16 : 2 = 8       32 : 4 = 8       56 : 7 = 8       40 : 5 = 8

8 x 2 = 16       8 x 4 =32       8 x 7 =56 .     8 x 5 =40 

16 : 8 = 2       32 : 8 =4        56 : 8 =7        40 : 8 =5 

16 : 2 = 8       32 : 4 = 8       56 : 7 = 8       40 : 5 = 8

cái bài này bạn thuộc phép nhân chia của nó là làm dễ lắm nha

\(=\dfrac{7^{16}\cdot2^{16}\cdot7^{32}\cdot3^{32}\cdot7^{48}\cdot5^{48}}{5^{16}\cdot2^{16}\cdot5^{32}\cdot3^{32}\cdot7^{96}}\)

\(=\dfrac{7^{96}\cdot2^{16}\cdot3^{32}\cdot5^{48}}{7^{96}\cdot2^{48}\cdot5^{48}}=\dfrac{3^{32}}{2^{32}}=1.5^{32}\)