Tìm x,y biết :

a) \(\frac{3}{4}x+\frac{1}{5}=-\frac{1}{2}\)

b)\(-\frac{4}{5}+\left(\frac{1}{3}:y\right)=-\frac{5}{6}\)

Tính nhanh giá trị biểu thức sau:

a) \(-\frac{9}{10}\cdot\frac{5}{14}+\frac{1}{10}\cdot\left(-\frac{9}{2}\right)+\frac{1}{7}\cdot\left(-\frac{9}{10}\right)\)

^{b)\(\left(\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+\frac{1}{6}+\frac{1}{11}\right)\cdot132\)}

^{c)\(-\frac{2}{3}\cdot\left(\frac{8}{9}\cdot\frac{8}{13}-\frac{8}{27}\cdot\frac{3}{13}+\frac{4}{3}\cdot\frac{22}{39}\right)\)}