1,Tính nhanh nếu có thể :
a, $\frac{3}{5}$+$\frac{1}{5}$.$\frac{-17}{9}$
b,($\frac{-4}{15}$-$\frac{18}{19}$)-($\frac{20}{19}$+$\frac{11}{15}$)
c,$\frac{1-\frac{8}{7}+\frac{8}{11}+\frac{8}{15}}{0,875-1+\frac{7}{11}+\frac{7}{15}}$
2,tìm x:
a,
3.(5.x+$\frac{2}{3}$^2)= $\frac{4}{3}$