3/5+4/7+2/5+1/7+2/7
=(3/5+2/5)+(4/7+1/7+2/7)
=1+1=2
4/9+8/9+12/9+16/9+48/9+56/9+44/9+52/9
=(4/9+16/9)+(8/9+12/9)+(48/9+52/9)+(56/9+44/9)
=20/9+20/9+100/9+100/9
=240/9
=80/3
HT
\(a,\frac{3}{5}+\frac{4}{7}+\frac{2}{5}+\frac{1}{7}+\frac{2}{7}=\left(\frac{3}{5}+\frac{2}{5}\right)+\left(\frac{4}{7}+\frac{1}{7}+\frac{2}{7}\right)=1+1=2\)
\(b,\frac{4}{9}+\frac{8}{9}+\frac{12}{9}+\frac{16}{9}+\frac{48}{9}+\frac{56}{9}+\frac{44}{9}+\frac{52}{9}\)
Phần này bạn xem lại đầu bài nhé!
TL
= 2
=80/3
nha HT
k cho mik