Question

Rút gọn các phân số sau:

a/ \(\frac{7.11+32.7}{21.25+18.21}\)

b/ \(\frac{1+2+3+...+9+10}{11+12+13+...+18+19}\)

c/\(\frac{11.13+22.26+33.39}{22.26+44.52+66.78}\)

d/ \(\frac{24.315+3.561.8+4.6.124}{1+3+5....+99-500}\)

Answer 1

c/      \(\frac{11.13+22.26+33.39}{22.26+44.52+66.78}=\frac{11.13+11.2.13.2+11.3.13.3}{11.2.13.2+11.2.2.13.2.2+11.2.3.13.2.3}=\frac{11.13.\left(1+2.2+3.3\right)}{11.2.13.2\left(1+2.2+3.3\right)}=\frac{11.13}{11.2.13.2}=\frac{1}{4}\)

 

Answer 2

a/7.(11+32)      7.43    301   1

  ----------------=---------=------=----

  21.(25+18)    21.43   903  3