B=\(\frac{5}{7}.\frac{14}{11}-\frac{5}{7}.\frac{5}{11}-\frac{5}{11}.\frac{2}{7}\)

C=\(1+\frac{2}{6}+\frac{2}{12}+\frac{2}{20}+\frac{2}{30}+\frac{2}{42}\)

D=\(\frac{0,75-0,6+\frac{3}{19}+\frac{3}{19}}{2,75-2,2+\frac{11}{19}+\frac{11}{91}}\)

(6:\(\frac{3}{5}\)-\(1\frac{1}{7}\)x \(\frac{7}{8}\)):(\(4\frac{1}{5}\)x \(\frac{10}{11}\)+\(5\frac{2}{11}\)) x \(1\frac{2}{5}\)x\(2\frac{1}{7}\)

Tính :

a) 3,5 x 2 + 1,25 x 4

b) \(\frac{3}{4}+2\times\left(\frac{1}{2}-\frac{1}{15}\right)\)

c) \(\frac{7}{11}\times\frac{1}{19}+\frac{7}{11}\times\frac{8}{19}-\frac{4}{11}\)

3/5 + 1/4 , 5 + 1/3 , 11/9 - 6/7 , 7/2 - 12 , 9/14 - 2/7.

A = 11 \(\frac{2}{1\times3}\)+11\(\frac{2}{3\times5}\)+ 11 \(\frac{2}{5\times7}\)+ 11\(\frac{2}{7\times9}\)+ 11\(\frac{2}{9\times11}\)

giúp mk với nhanh nhé

 đề bài : Tính nhanh tổng A

1, Tính :  

a ) \(3\frac{17}{24}+2\frac{8}{15}+1\frac{7}{8}\)

b) \(2\frac{4}{11}+5\frac{2}{3}+\frac{7}{11}\)

b=(6:9\(\frac{3}{5}\) -1\(\frac{1}{7}\) x\(\frac{7}{8}\) ):(4\(\frac{1}{5}\)x\(\frac{10}{11}\) +5\(\frac{2}{11}\) )x1\(\frac{2}{5}\) )x1\(\frac{2}{5}\) x2\(\frac{1}{7}\) 

mk đang cần gấp ai nhanh mk tk

1) \(79\frac{19}{35}.\frac{7}{90}+15\frac{16}{35}.\frac{7}{90}\)

2)\(\left(3\frac{1}{5}-\frac{1}{11}\right).11\)

3)\(4\frac{1}{5}:\left(2\frac{1}{3}.1\frac{2}{5}\right)\)

4)\(13,2.\frac{15}{64}-\left(\frac{4}{5}+\frac{2}{3}\right):3\frac{2}{3}\)