Tự luận:
Câu 1:
a,
$\frac{-2}{3}+\frac{4}{15}$
$=\frac{-10}{15}+\frac{4}{15}$
$=\frac{-6}{15}= \frac{-2}{5}$
b,
$\frac{-3}{7}.\frac{5}{11}+\frac{-3}{7}.\frac{6}{11}+2\frac{3}{7}$
$= \frac{-3}{7}.(\frac{5}{11}+\frac{6}{11})+\frac{17}{7}$
$= \frac{-3}{7}+\frac{17}{7}$
$= 2$
c,
$5\frac{1}{7}-(3\frac{2}{3}+4\frac{1}{3})$
$= \frac{36}{7}-(\frac{11}{3}+\frac{13}{3})$
$= \frac{36}{7}-8$
$= -\frac{20}{7}$
Câu 2:
1/
a, $2x-\frac{5}{2}= 1,5$
$2x=1,5+\frac{5}{2}$
$2x=4$
$x=2$
b, $\frac{2}{3}-\frac{1}{3}x= \frac{5}{6}$
$\frac{1}{3}x=\frac{2}{3}-\frac{5}{6}= -\frac{1}{6}$
$x= -\frac{1}{2}$
