Bài 2 :
a) {$\frac{1313131313:101010101}{3939393939:101010101}$ }$ =$\frac{13}{39}$ =$\frac{13:13}{39:13}$ =$\frac{1}{3}$
b) $\frac{187187}{221221}$ =$\frac{187187:1001}{221221:1001}$ =$\frac{187}{221}$
Bài 1 :
$\frac{-3}{13}$ .$\frac{2}{6}$ + $\frac{6}{13}$ . $\frac{-5}{12}$
=$\frac{-3}{13}$ . $\frac{4}{12}$ + $\frac{6}{13}$ . $\frac{-5}{12}$
=( $\frac{-3}{13}$ . $\frac{4}{12}$ ) + ($\frac{6}{13}$ . $\frac{-5}{12}$ )
=$\frac{-4}{52}$ + $\frac{-5}{26}$
=$\frac{-2}{26}$ + $\frac{-5}{26}$
=$\frac{-7}{26}$
Cho mik 5 sao và câu trả lời hay nhất nha bạn
