\(3+\frac{2}{5}-\frac{3}{4}\times\frac{4}{5}\)

\(=3+\frac{2}{5}-\frac{3}{4}\)

\(=\frac{3\times20+2\times4-3\times5}{20}\)

\(=\frac{60+8-15}{20}\)

\(=\frac{68-15}{20}\)

\(=\frac{53}{20}\)

\(5-\frac{7}{9}+\frac{2}{3}-\frac{5}{6}:\frac{4}{9}\)

\(=5-\frac{7}{9}+\frac{2}{3}-\frac{45}{24}\)

\(=\frac{5\times72-7\times8+2\times24-45\times3}{72}\)

\(=\frac{360-56+48-135}{72}\)

\(=\frac{217}{72}\)

=0,8286801719

mk chỉ cần cộng tủ số

4+5+6+7=22/5+5=47/5

k cho mk nha

mk nhanh nhất

\(\frac{4}{5}+\frac{5}{5}+\frac{6}{5}+\frac{7}{5}+5\) = \(\left(\frac{4}{5}+\frac{6}{5}\right)+\left(\frac{5}{5}+5\right)+\frac{7}{5}\) 

= \(2+6+\frac{7}{5}\) = \(8+\frac{7}{5}=\frac{8}{1}+\frac{7}{5}=\frac{40}{5}+\frac{7}{5}=\frac{47}{5}\)

K cho mk nha mk nhanh nhất

\(\frac{4}{5}\)+ \(\frac{5}{4}\)= \(\frac{16}{20}\)+ \(\frac{25}{20}\)

                    =  \(\frac{41}{20}\)

tk nhé

\(\frac{4}{5}+\frac{5}{4}=\frac{16}{20}+\frac{25}{20}=\frac{41}{20}\)

k mik nhé 

mik đang âm

\(\frac{5}{4}+\frac{4}{5}=\frac{25}{20}+\frac{16}{20}\)

                \(=\frac{41}{20}\)

kb với mik nhá

\(\frac{5}{4}+\frac{4}{5}=\frac{25}{20}+\frac{16}{20}=\frac{41}{20}\)

a) 5/6 > 4/5

b) 3/5 = 12/20

c) 5/12 < 3/4

a,>

b,=

c,<

\(a.\frac{3}{7}.\frac{5}{6}+\frac{5}{6}.\frac{4}{7}=\left(\frac{3}{7}+\frac{4}{7}\right).\frac{5}{6}=1.\frac{5}{6}=\frac{5}{6}\)

\(b.\frac{1}{6}:\frac{4}{5}+\frac{1}{8}:\frac{4}{5}=\left(\frac{1}{6}+\frac{1}{8}\right):\frac{4}{5}=\left(\frac{4}{24}+\frac{3}{24}\right):\frac{4}{5}=\frac{7}{24}:\frac{4}{5}=\frac{7.5}{24.4}\)\(=\frac{35}{96}\)

\(c.\frac{1}{6}:\frac{4}{5}-\frac{1}{8}:\frac{4}{5}=\left(\frac{1}{6}-\frac{1}{8}\right):\frac{4}{5}=\left(\frac{4}{24}-\frac{3}{24}\right):\frac{4}{5}\)\(=\frac{1}{24}:\frac{4}{5}=\frac{1.5}{24.4}=\frac{5}{96}\)

a) \(\frac{3}{7}\cdot\frac{5}{6}+\frac{5}{6}\cdot\frac{4}{7}\)

\(=\left(\frac{3}{7}+\frac{4}{7}\right)\cdot\frac{5}{6}\)

\(=1\cdot\frac{5}{6}\)

\(=\frac{5}{6}\)

b) \(\frac{1}{6}:\frac{4}{5}+\frac{1}{8}:\frac{4}{5}\)

\(=\left(\frac{1}{6}+\frac{1}{8}\right):\frac{4}{5}\)

\(=\frac{7}{24}:\frac{4}{5}\)

\(=\frac{35}{96}\)

c) \(\frac{1}{6}:\frac{4}{5}-\frac{1}{8}:\frac{4}{5}\)

\(=\left(\frac{1}{6}-\frac{1}{8}\right):\frac{4}{5}\)

\(=\frac{1}{24}:\frac{4}{5}\)

\(=\frac{5}{96}\)

a)\(\dfrac{5}{7}+\dfrac{4}{9}=\dfrac{45}{63}+\dfrac{28}{63}=\dfrac{73}{63}\) ; \(\dfrac{9}{11}+\dfrac{3}{8}=\dfrac{72}{88}+\dfrac{33}{88}=\dfrac{105}{88}\)

\(\dfrac{4}{5}-\dfrac{2}{3}=\dfrac{12}{15}-\dfrac{10}{15}=\dfrac{2}{15}\); \(\dfrac{16}{25}-\dfrac{2}{5}=\dfrac{16}{25}-\dfrac{10}{25}=\dfrac{6}{25}\)

b)\(5+\dfrac{3}{5}=\dfrac{25}{5}+\dfrac{3}{5}=\dfrac{28}{5};10-\dfrac{9}{16}=\dfrac{160}{16}-\dfrac{9}{16}=\dfrac{151}{16}\)

\(\dfrac{2}{3}-\left(\dfrac{1}{6}+\dfrac{1}{8}\right)=\dfrac{2}{3}-\left(\dfrac{8}{48}+\dfrac{6}{48}\right)=\dfrac{2}{3}-\dfrac{14}{48}=\dfrac{32}{48}-\dfrac{14}{48}=\dfrac{3}{8}\)

a ) -33/56

b )-17/63

c ) 18/5

a ) - 33/56

b ) - 17/63

c ) 18/5

Đề bài là gì bạn ơi có chỗ ...

chưa có đề bạn ơi! Y_Y

Hok tốt ^_^