\(26\dfrac{1}{5}.\dfrac{3}{4}-\dfrac{3}{4}.44\dfrac{1}{5}\)

\(=\dfrac{3}{4}.\left(26\dfrac{1}{5}-44\dfrac{1}{5}\right)\)

\(=\dfrac{3}{4}.-18\)

\(=-\dfrac{27}{2}\)

  \(\dfrac{37}{4}+\dfrac{44}{7}\) + \(\dfrac{38}{5}\) + \(\dfrac{26}{3}\) + \(\dfrac{1}{3}\) + \(\dfrac{5}{7}\) + \(\dfrac{3}{4}\)

= ( \(\dfrac{37}{4}+\) \(\dfrac{3}{4}\)) + ( \(\dfrac{26}{3}+\dfrac{1}{3}\)) + (\(\dfrac{44}{7}+\dfrac{5}{7}\)) + \(\dfrac{38}{5}\)

= \(\dfrac{40}{4}\) + \(\dfrac{27}{3}\) + \(\dfrac{49}{7}\) + \(\dfrac{38}{5}\)

= 10 + 9 + 7 + \(\dfrac{38}{5}\)

=26 + 7,6

= 33,6 

\(\frac{3}{4}.26\frac{1}{5}.\frac{3}{4}.44\frac{1}{5}=\frac{3}{4}.\frac{131}{5}.\frac{3}{4}.\frac{221}{5}=651,3975\)

\(a,\dfrac{4}{5}+\dfrac{1}{4}\times\dfrac{2}{5}\)

\(=\dfrac{4}{5}+\dfrac{1}{10}\)

\(=\dfrac{8}{10}+\dfrac{1}{10}\)

\(=\dfrac{9}{10}\)

\(---\)

\(b,\dfrac{7}{12}+\dfrac{3}{44}:\dfrac{3}{8}-\dfrac{1}{4}\)

\(=\left(\dfrac{7}{12}-\dfrac{1}{4}\right)+\dfrac{3}{44}\cdot\dfrac{8}{3}\)

\(=\left(\dfrac{7}{12}-\dfrac{3}{12}\right)+\dfrac{8}{44}\)

\(=\dfrac{4}{12}+\dfrac{8}{44}\)

\(=\dfrac{44}{132}+\dfrac{24}{132}\)

\(=\dfrac{68}{132}\)

\(=\dfrac{17}{33}\)

#\(Toru\)

44/7 + 38/5 +78/9+ 2/5 + 5/7 +1/3+3/4+1981

= ( 44/7 + 5/7 ) + ( 38/5 +2/5 ) + 26/3 + 1/3 +3/4 +1981

= ( 44/7 + 5/7 ) + ( 38/5 +2/5 ) + ( 26/3 + 1/3 ) + 3/4 + 1981

= 7 + 8 + 9 + 3/4 + 1981

= 3/4 + 2005

= 8023/4

Rất tiếc cái này mình chưa học

lớp 5 chưa học lũy thừa mà bạn

Sai đề phải không. Nếu là 5⁴⁹ thì làm thế này

C = 5^{2 -} 5^{3 +}5⁴-5⁵+......-5⁴⁹+5⁵⁰

5C= 5³ - 5⁴ + 5⁵ - 5⁶ +......-5⁵⁰+5⁵¹

5C+C=4C=5⁵¹+5²

Vậy C = 5⁵¹+5²/4

loạn đầu mất tiêu lun oy`. ko bít hôm trước mama tui cho tui lm bài này ở đâu nữa. AAAAA, để tui kiểm tra lại đã

nhiều khi điệu quá cx ko tốt đâu bạn

a: x-4/5=3/7

=>x=3/7+4/5=43/35

b: x+3/7=4/5

=>x=4/5-3/7=13/35

c: 19/20-x=8/5-3/4

=>19/20-x=32/20-15/20=17/20

=>x=2/20=1/10

d: =>4/5*x=2/21

=>x=2/21:4/5=5/42

e: =>x:7/9=6/8

=>x=6/8*7/9=3/4*7/9=21/36=7/12

f: =>x/6=2/3-1/3=1/3

=>x=2