1/
a/$\frac{-5}{4}$ +$\frac{1}{2}$ -$\frac{7}{3}$
=$\frac{15}{12}$ +$\frac{6}{12}$ -$\frac{28}{12}$
=$\frac{-7}{12}$
b/
$\frac{19}{43}$ .$\frac{27}{17}$ -$\frac{19}{43}$ .$\frac{10}{17}$ +$\frac{24}{43}$
=$\frac{19}{43}$.( $\frac{27}{17}$ -$\frac{19}{43}$ +$\frac{24}{43}$
=$\frac{19}{43}$ ) +$\frac{24}{43}$
=1
c/1,6.$\frac{5}{12}$ -(4-$\frac{3}{5}$ ):$\frac{17}{4}$
= $\frac{2}{3}$ -$\frac{4}{5}$
=$\frac{-2}{15}$
2/
a/ $\frac{11}{15}$ -x=$\frac{7}{6}$
=> x=$\frac{11}{15}$ -$\frac{7}{6}$ =$\frac{-13}{30}$
b/
$\frac{2}{3}$x-$\frac{7}{8}$ =$\frac{1}{4}$
=> $\frac{2}{3}$x= $\frac{9}{8}$
=> x=$\frac{27}{16}$
3/
Đóng được tất cả: 150: 3/4= 200 chai
