3 2 phần 5 =17 phần 5 ; 2 4 phần 9=22 phần 9; 7 3 phần 8= 59 phần 8 ; 15 1 phần 10= 151 phần 10

nhớ k cho mình đúng nha

Ta có : 

\(\frac{1}{2}=1\div2=0,5\)

\(\frac{2}{3}=2\div3=0,666...\)

\(\frac{3}{4}=3\div4=0,75\)

\(\frac{4}{5}=4\div5=0,8\)

\(\frac{5}{6}=5\div6=0,8333...\)

\(\frac{6}{7}=6\div7=0,8671...\)

\(\frac{7}{8}=7\div8=0,875\)

\(\frac{8}{9}=8\div9=0,888...\)

Vậy các phân số có thể là : \(\frac{1}{2};\frac{3}{4};\frac{4}{5};\frac{7}{8}\)

1/2;4/

a) \(\frac{15}{10}=1,5\)        \(\frac{675}{10}=6,75\)          \(\frac{7}{10}=0,7\)      

\(\frac{79}{100}=0,79\)       \(\frac{5}{100}=0,05\)           \(\frac{67}{100}=0,67\)

b) \(\frac{1}{2}=1\div2=0,5\)                   \(\frac{3}{4}=3\div4=0,75\)

\(\frac{15}{8}=15\div8=1,875\)              \(\frac{7}{25}=7\div25=0,28\)

\(\frac{19}{30}=19\div30=0,63\)              \(\frac{21}{125}=21\div125=0,168\)

thời xưa chắc không có ghi vở

\(3\frac{1}{2}=\frac{3.2+1}{2}=\frac{7}{2}\)

\(13\frac{2}{3}=\frac{13.3+2}{3}=\frac{41}{3}\)

\(5\frac{7}{8}=\frac{5.8+7}{8}=\frac{47}{8}\)

\(17\frac{1}{4}=\frac{17.4+1}{4}=\frac{69}{4}\)

\(4\frac{2}{9}=\frac{4.9+2}{9}=\frac{38}{9}\)

\(21\frac{5}{9}=\frac{21.9+5}{9}=\frac{194}{9}\)

\(10\frac{5}{8}=\frac{10.8+5}{8}=\frac{85}{8}\)

\(14\frac{1}{5}=\frac{14.5+1}{5}=\frac{71}{5}\)

1a,\(\frac{8}{5}\)=1\(\frac{3}{5}\)b,\(\frac{9}{2}\)=4\(\frac{1}{2}\)c,\(\frac{7}{4}\)=1\(\frac{3}{4}\)d,\(\frac{10}{3}\)

2a,1\(\frac{3}{4}\)+1\(\frac{5}{8}\)=\(\frac{7}{4}\)+\(\frac{13}{8}\)=\(\frac{14}{8}\)+\(\frac{13}{8}\)=\(\frac{27}{8}\)b,3\(\frac{4}{5}\)x2\(\frac{6}{8}\)=\(\frac{19}{5}\)x\(\frac{22}{8}\)=\(\frac{418}{40}\)=\(\frac{209}{20}\)

3,3\(\frac{2}{5}\)=\(\frac{17}{5}\),3\(\frac{4}{5}\)=\(\frac{19}{5}\)    ,       8\(\frac{2}{4}\)=\(\frac{34}{4}\),10\(\frac{6}{7}\)=\(\frac{76}{7}\)    ,       5\(\frac{1}{2}\)=\(\frac{11}{2}\),5\(\frac{3}{4}\)=\(\frac{23}{4}\)

=>\(\frac{17}{5}\)<\(\frac{19}{5}\)=>3\(\frac{2}{5}\)<3\(\frac{4}{5}\)       =>\(\frac{34}{4}\)<\(\frac{76}{7}\)=>8\(\frac{2}{4}\)<10\(\frac{6}{7}\)      =>\(\frac{11}{2}\)<\(\frac{23}{4}\)=>5\(\frac{1}{2}\)<5\(\frac{3}{4}\)

k mik nha ......