a) \(\frac{3}{5}+\frac{6}{11}+\frac{7}{13}+\frac{5}{11}+\frac{2}{5}+\frac{19}{13}=\left(\frac{3}{5}+\frac{2}{5}\right)+\left(\frac{6}{11}+\frac{5}{11}\right)+\left(\frac{7}{13}+\frac{19}{13}\right)=1+1+2=4\)

b) \(\frac{6}{5}\times\frac{3}{8}+\frac{5}{8}\times\frac{6}{5}-\frac{4}{5}=\frac{6}{5}\times\left(\frac{3}{8}+\frac{5}{8}\right)-\frac{4}{5}=\frac{6}{5}-\frac{4}{5}=\frac{2}{5}\)

c) \(\frac{4\times5\times6\times7\times8}{8\times10\times12\times14\times16}=\frac{1}{2\times2\times2\times2\times2}=\frac{1}{32}\)

a, \(\frac{3}{5}+\frac{6}{11}+\frac{7}{13}+\frac{6}{11}+\frac{2}{5}+\frac{19}{13}\)

\(=\left(\frac{3}{5}+\frac{2}{5}\right)+\left(\frac{7}{13}+\frac{19}{13}\right)+\left(\frac{6}{11}+\frac{6}{11}\right)\)

\(=1+2+\frac{12}{11}\)

\(=3+\frac{12}{11}\)

\(=\frac{45}{11}\)

1.B

2.C

~HT~

CÂU:2C      CÂU:1B

\(6\frac{8}{5}-6\frac{5}{5}=\frac{38}{5}-\frac{35}{5}=\frac{3}{5}\)

\(\frac{40}{20}=2\)                  \(\frac{25}{5}=5\)

câu trả lời là:3/5

40/20=2

25/5=5

k cho 1 cái rồi k lại

\(4\frac{5}{6}:5\frac{6}{7}\)

\(=\frac{29}{6}:\frac{41}{7}\)

\(=\frac{29}{6}x\frac{7}{41}\)

\(=\frac{203}{246}\)

k mk mk k lại nha

\(6\frac{8}{5}+5\frac{9}{6}\)

\(=\frac{38}{5}+\frac{39}{6}\)

\(=\frac{228}{30}+\frac{195}{30}\)

\(=\frac{423}{30}\)

\(5\frac{1}{6}:6\frac{1}{5}=\frac{31}{6}:\frac{31}{5}=\frac{5}{6}\)

Bạn biến đổi ra phân số ra rồi chia như bình thường!!!

Đồng ý thì k nha!!!

\(\frac{11}{9}-\frac67\)

\(=\frac{77}{63}-\frac{54}{63}=\frac{77-54}{63}=\frac{23}{63}\)

\(\frac{7}{10}-\frac25=\frac{7}{10}-\frac{4}{10}=\frac{7-4}{10}=\frac{3}{10}\)

\(\frac72-2=\frac72-\frac42=\frac{7-4}{2}=\frac32\)

\(\frac65\times\frac38=\frac{6\times3}{5\times8}=\frac{18}{40}=\frac{9}{20}\)

\(\frac25:\frac32=\frac25\times\frac23=\frac{2\times2}{5\times3}=\frac{4}{15}\)

\(5:\frac57=5\times\frac75=7\)

\(\frac73:4=\frac{7}{3\times4}=\frac{7}{12}\)

911​−76​

\(= \frac{77}{63} - \frac{54}{63} = \frac{77 - 54}{63} = \frac{23}{63}\)

\(\frac{7}{10} - \frac{2}{5} = \frac{7}{10} - \frac{4}{10} = \frac{7 - 4}{10} = \frac{3}{10}\)

\(\frac{7}{2} - 2 = \frac{7}{2} - \frac{4}{2} = \frac{7 - 4}{2} = \frac{3}{2}\)

\(\frac{6}{5} \times \frac{3}{8} = \frac{6 \times 3}{5 \times 8} = \frac{18}{40} = \frac{9}{20}\)

\(\frac{2}{5} : \frac{3}{2} = \frac{2}{5} \times \frac{2}{3} = \frac{2 \times 2}{5 \times 3} = \frac{4}{15}\)

\(5 : \frac{5}{7} = 5 \times \frac{7}{5} = 7\)

\(\frac{7}{3} : 4 = \frac{7}{3 \times 4} = \frac{7}{12}\)

ai tính song là banh não

Tớ ko bít phải làm sao bây giờ ?

tô ? ko ? bít ?

-_-!  ai thick tích cu  !

a, 6/9+5/7+1/3=2/3+5/7+1/3=5/7+1=12/7

b, 17/7+6/5-20/14=17/7+6/5-10/7=6/5+1=11/5

c,2/5x1/4+3/4x2/5=2/5x(1/4+3/4)=2/5x1=2/5

d, 6/11:4/6+5/11:2/3=6/11:2/3+5/11:2/3=(6/11+5/11):2/3=3/2

nha