a) \(-\dfrac{1}{6}+\dfrac{5}{13}-\dfrac{5}{13}-\dfrac{11}{12}=-\dfrac{1}{6}-\dfrac{11}{12}=-\dfrac{13}{12}\)
b) \(\dfrac{3^4\cdot4-3^6}{3^5\cdot5+10\cdot3^6}=\dfrac{3^4\left(4-3^2\right)}{3^4\left(15+10\cdot3^2\right)}=\dfrac{4-9}{15+90}=-\dfrac{1}{21}\)
c) \(\left(1-\dfrac{3}{4}\right)^2+\left|-\dfrac{4}{5}\right|-\dfrac{29}{80}\cdot2019^2\) (Câu này thì bạn bấm máy cho nhanh :))