Question

[Christina]

Thực hện phép tính hợp lí( nếu có thể)

a,\(\left(3\dfrac{1}{5}-2\dfrac{1}{3}+\dfrac{5}{6}\right)\)-\(\left(1,5-\dfrac{2}{3}+\dfrac{1}{6}\right)\)

b,\(\dfrac{\left(3\dfrac{1}{5}.1,4-2,5.\dfrac{7}{108}\right):2\dfrac{7}{18}+4\dfrac{1}{2}.0,1}{70,5-5,28:7\dfrac{1}{2}}\)

HELP ME, MÌNH CẦN GẤP

Answer 1

[Khánh Linh]

a, (3\(\dfrac{1}{5}-2\dfrac{1}{3}+\dfrac{5}{6}\)) - (1,5 - \(\dfrac{2}{3}+\dfrac{1}{6}\))

= \(\dfrac{16}{5}-\dfrac{7}{3}+\dfrac{5}{6}-\dfrac{3}{2}+\dfrac{2}{3}-\dfrac{1}{6}\)

= (\(\dfrac{16}{5}-\dfrac{3}{2}\)) - (\(\dfrac{7}{3}-\dfrac{2}{3}\)) + (\(\dfrac{5}{6}-\dfrac{1}{6}\))

= \(\dfrac{17}{10}-\dfrac{5}{3}+\dfrac{2}{3}\)
= \(\dfrac{17}{10}-1\)

= \(\dfrac{7}{10}\)

@Christina

Answer 2

[Khánh Linh]

b, \(\dfrac{\left(3\dfrac{1}{5}.1,4-2,5.\dfrac{7}{108}\right):2\dfrac{7}{18}+4\dfrac{1}{2}.0,1}{70,5-5,28:7\dfrac{1}{2}}\)

= \(\dfrac{\left(\dfrac{16}{5}.\dfrac{7}{5}-\dfrac{5}{2}.\dfrac{7}{108}\right):\dfrac{43}{18}+\dfrac{9}{2}.\dfrac{1}{10}}{\dfrac{141}{2}-\dfrac{132}{25}:\dfrac{15}{2}}\)

= \(\dfrac{\left(\dfrac{112}{25}-\dfrac{35}{216}\right):\dfrac{43}{18}+\dfrac{9}{20}}{\dfrac{141}{2}-\dfrac{88}{125}}\)

= \(\dfrac{\dfrac{112}{25}:\dfrac{43}{18}-\dfrac{25}{216}:\dfrac{43}{18}+\dfrac{9}{20}}{\dfrac{17449}{250}}\)

= \(\dfrac{\dfrac{2016}{1075}-\dfrac{25}{516}+\dfrac{9}{20}}{\dfrac{17449}{250}}\)

= \(\dfrac{\dfrac{2016}{1075}+\dfrac{259}{645}}{\dfrac{17449}{250}}\)
= \(\dfrac{\dfrac{7343}{3225}}{\dfrac{17449}{250}}\)

@Christina