16/5

17/4

a. 7/2 - 3/10 = 16/5

b. (4/6 + 5):4/3=17/3 :4/3=17/4

a) \(6-\dfrac{5}{2}-\dfrac{3}{10}=\dfrac{7}{2}-\dfrac{3}{10}=\dfrac{16}{5}\)

b) \(\dfrac{4}{6}\div\dfrac{4}{3}+5\div\dfrac{4}{3}\)

    \(=\dfrac{1}{2}+\dfrac{15}{4}\)

     \(=\dfrac{17}{4}\)

21/10

17/4

a) 6/1x 2/5-3/10

= 12/5- 3/10

= 21/10

b) (4/6+5):4/3

= 17/3x 3/4

= 17/4

a) 6 : 5/2 - 3/10 = 12/5 - 3/10 = 21/10

b) 4/6 : 4/3 + 5 : 4/3 = 1/2 + 5 : 4/3 = 1/2 + 15 /4 = 17/4

a)

`6:5/2-3/10`

`=6xx2/5-3/10`

`=12/5-3/10`

`=24/10-3/10`

`=21/10`

b)

`4/6:4/3+5:4/3`

`=2/3xx3/4+5xx3/4`

`=3/4xx(2/3+5)`

`=3/4xx(2/3+15/3)`

`=3/4xx17/3`

`=17/4`

\(a,6:\dfrac{5}{2}-\dfrac{3}{10}\\ =\dfrac{6}{1}:\dfrac{5}{2}-\dfrac{3}{10}\\ =\dfrac{6}{1}\times\dfrac{5}{2}-\dfrac{3}{10}\\ =\dfrac{12}{5}-\dfrac{3}{10}\\ =\dfrac{12\times2}{5\times2}-\dfrac{3}{10}\\ =\dfrac{24}{10}-\dfrac{3}{10}\\ =\dfrac{21}{10}\) 

\(b,\dfrac{4}{6}:\dfrac{4}{3}+5:\dfrac{4}{3}\\ =\dfrac{4}{6}:\dfrac{4}{3}+\dfrac{5}{1}:\dfrac{4}{3}\\ =\dfrac{4}{3}:\left(\dfrac{4}{6}+\dfrac{5}{1}\right)\\ =\dfrac{4}{3}:\left(\dfrac{4}{6}+\dfrac{5\times6}{1\times6}\right)\\ =\dfrac{4}{3}:\left(\dfrac{4}{6}+\dfrac{30}{6}\right)\\ =\dfrac{4}{3}:\dfrac{34}{6}\\ =\dfrac{4}{3}:\dfrac{17}{3}\\ =\dfrac{4}{3}\times\dfrac{3}{17}\\=\dfrac{12}{51} \\ =\dfrac{4}{17}.\)

\(a,6:\dfrac{5}{2}-\dfrac{3}{10}=6\times\dfrac{5}{2}-\dfrac{3}{10}=\dfrac{12}{5}-\dfrac{3}{10}=\dfrac{24}{10}-\dfrac{3}{10}=\dfrac{21}{10}\)

\(b,\dfrac{4}{6}:\dfrac{4}{3}+5:\dfrac{4}{3}=\dfrac{4}{6}\times\dfrac{3}{4}+5\times\dfrac{3}{4}=\dfrac{2}{4}+\dfrac{15}{4}=\dfrac{17}{4}\)

a) Với a = 3,05 thì ta có:

\(a\times2,46\) \(=3,05\times2,46=7,503\)

b) Với \(a=\dfrac{15}{8}\) thì ta có:

\(\left(\dfrac{5}{6}+\dfrac{7}{12}\right):a\) \(=\left(\dfrac{5}{6}+\dfrac{7}{12}\right):\dfrac{15}{8}\) \(=\left(\dfrac{10}{12}+\dfrac{7}{12}\right)\times\dfrac{8}{15}\) \(=\dfrac{17}{12}\times\dfrac{8}{15}\) \(=\dfrac{34}{45}\)

a) Thay a=3,05 vào 2,46a, ta được:

\(2.46\cdot3.05=7.503\)

b) Thay \(a=\dfrac{15}{8}\) vào biểu thức \(\left(\dfrac{5}{6}+\dfrac{7}{12}\right):a\), ta được:

\(\left(\dfrac{5}{6}+\dfrac{7}{12}\right):\dfrac{15}{8}\)

\(=\dfrac{17}{12}\cdot\dfrac{8}{15}=\dfrac{34}{45}\)

a) \(\dfrac{9}{5}+\dfrac{9}{5}:\dfrac{9}{5}\)

\(=\dfrac{9}{5}+\dfrac{9}{5}\times\dfrac{5}{9}\)

\(=\dfrac{9}{5}+1\)

\(=\dfrac{14}{5}\)

b) \(\dfrac{7}{5}-\dfrac{1}{2}\times\dfrac{1}{3}\)

\(=\dfrac{7}{5}-\dfrac{1}{6}\)

\(=\dfrac{42}{30}-\dfrac{5}{30}\)

\(=\dfrac{37}{30}\)

\(a,\dfrac{9}{5}+\dfrac{9}{5}:\dfrac{9}{5}\)

\(=\dfrac{9}{5}+\dfrac{9}{5}\times\dfrac{5}{9}\)

\(=\dfrac{9}{5}+1\)

\(=\dfrac{9}{5}+\dfrac{5}{5}\)

\(=\dfrac{14}{5}\)

\(b,\dfrac{7}{5}-\dfrac{1}{2}\times\dfrac{1}{3}\)

\(=\dfrac{7}{5}-\dfrac{1}{6}\)

\(=\dfrac{42}{30}-\dfrac{5}{30}\)

\(=\dfrac{37}{30}\)

a: \(2\dfrac{3}{5}+1\dfrac{2}{5}\cdot\dfrac{31}{2}\)

\(=\dfrac{13}{5}+\dfrac{7}{5}\cdot\dfrac{31}{2}\)

\(=\dfrac{26}{10}+\dfrac{217}{10}=\dfrac{243}{10}\)

b: \(4\dfrac{3}{4}-3\dfrac{2}{3}:1\dfrac{1}{6}\)

\(=\dfrac{19}{4}-\dfrac{11}{3}:\dfrac{7}{6}\)

\(=\dfrac{19}{4}-\dfrac{11}{3}\cdot\dfrac{6}{7}\)

\(=\dfrac{19}{4}-\dfrac{22}{7}\)

\(=\dfrac{19\cdot7-22\cdot4}{28}=\dfrac{45}{28}\)

\(a,=\dfrac{5}{6}+\dfrac{6}{7}\\ =\dfrac{35}{42}+\dfrac{36}{42}=\dfrac{71}{42}\\ b,=\dfrac{5}{6}+\dfrac{4}{9}\\ =\dfrac{15}{18}+\dfrac{8}{18}=\dfrac{23}{18}\)

 a) 3² . 5³ + 9² = 9 . 125 + 81

= 1 125 + 81 = 1 206

b) 8³ : 4² - 5² = 512 : 16 - 25 = 32 - 25 = 7

c) 3³ . 9² - 5².9 + 18 : 6 = 27 . 81 - 25 . 9 + 3

= 2 187 - 225 + 3 = 1 962 + 3 = 1 965

 a) 3² . 5³ + 9² = 9 . 125 + 81

= 1 125 + 81 = 1 206

b) 8³ : 4² - 5² = 512 : 16 - 25 = 32 - 25 = 7

c) 3³ . 9² - 5².9 + 18 : 6 = 27 . 81 - 25 . 9 + 3

= 2 187 - 225 + 3 = 1 962 + 3 = 1 965