\(\frac{3.7.8.13}{14\cdot15\cdot26}=\frac{3\cdot7\cdot8\cdot13}{2\cdot7\cdot3\cdot5\cdot2\cdot13}=\frac{8}{5\cdot2\cdot2}=\frac{8}{20}=\frac{2}{5}\)

\(\frac{3.7.8.13}{14.15.26}=\frac{3.7.2^3.13}{2.7.3.5.13.2}=\frac{1.7.2.1}{1.1.1.5.1.1}=\frac{14}{5}\)

\(\frac{11.8-11.3}{17-6}=\frac{11.\left(8-3\right)}{11}=\frac{11.5}{11}=\frac{1.5}{1}=\frac{5}{1}=5\)

\(\frac{-17.13+17.2}{11.2-11.9}=\frac{-17.13+\left(-17\right).2}{11.\left(2-9\right)}=\frac{-17.\left(-13+2\right)}{11.\left(-7\right)}=\frac{-17.\left(-11\right)}{11.\left(-7\right)}=\frac{-17.\left(-1\right)}{-1.\left(-7\right)}=\frac{17}{7}\)

\(\frac{7}{9.10^2-2.10^2}=\frac{7}{100\left(9-2\right)}=\frac{7}{100.7}=\frac{7}{700}=\frac{1}{100}\)

mình làm được tới đó thôi, hihi. 

Co ai biết lam con thu 5 ko, giúp minh voi. Dang mai minh nộp bai roi

\(\frac{-17.13+17.2}{11.2-11.19}=\frac{17.\left(-13\right)+17.2}{11.\left(2-9\right)}=\frac{17.\left(-11\right)}{11.\left(-7\right)}=\frac{17}{7}\)

\(\frac{-17.13+17.2}{11.2-11.19}=\frac{-17\left(13-2\right)}{11\left(2-19\right)}=\frac{-17.11}{11.\left(-17\right)}=1\)

\(\frac{-17.13+17.2}{11.2-11.19}=\frac{-17.\left(13-2\right)}{11.\left(2-19\right)}=\frac{-17.11}{11.\left(-17\right)}=1\)

_17*13+17\(\frac{-17\cdot13+17\cdot2}{11\cdot2-11\cdot19}=\frac{-221+34}{22-209}=\frac{-187}{-187}=\frac{1}{1}=1\)

a ) 7. b ) − 1 c ) − 1 2

d ) 1 4 e ) − 1 7 f ) 17 21

a, ta có \(\frac{2.\left(-13\right).9.10}{\left(-3\right).4.\left(-5\right).26}\)=\(\frac{2.\left(-13\right).\left(-3\right).\left(-3\right).2.\left(-5\right)}{\left(-3\right).2.2.\left(-5\right).\left(-2\right).\left(-13\right)}\)

rút gọn đi còn: \(\frac{-3}{-2}\)=\(\frac{3}{2}\)

15×8+15×4/12×3

= 15×(8+4)/12×3

=15×12/12×3

=15/3

=5

45/135=1/3;117/234=1/2;1515/2727=???;232323/494949=???