1. Tính:
a. \(\dfrac{11}{17}.\dfrac{19}{23}+\dfrac{11}{17}:\dfrac{23}{4}\)
b.\(\dfrac{-1}{2}-\dfrac{-3}{2}:\left(\dfrac{1}{2}-\dfrac{3}{4}\right)^2\)
c.\(\left(\dfrac{31}{15}+\dfrac{41}{25}-\dfrac{-51}{35}\right)\left(\dfrac{1}{2}-\dfrac{1}{3}-\dfrac{1}{6}\right)\)
d. \(\dfrac{-2}{3}+\dfrac{-3}{2}-\dfrac{-7}{8}\)
a,\(=\dfrac{11}{17}.\dfrac{19}{23}+\dfrac{11}{17}.\dfrac{4}{23}\)
\(=\dfrac{11}{17}.\left(\dfrac{19}{23}+\dfrac{4}{23}\right)\)
\(=\dfrac{11}{17}.1\)
\(=\dfrac{17}{17}\)
b,\(=-2:\left(\dfrac{-1}{4}\right)^2\)
\(=-2:\dfrac{1}{16}\)
\(=-32\)
c,\(=\left(\dfrac{31}{15}+\dfrac{41}{25}-\dfrac{-51}{35}\right)\left(\dfrac{3}{6}-\dfrac{2}{6}-\dfrac{1}{6}\right)\)
\(=\left(\dfrac{31}{15}+\dfrac{41}{25}-\dfrac{-51}{35}\right).0\)
\(=0\)
d,\(=\dfrac{-4}{6}+\dfrac{-9}{6}-\dfrac{-7}{8}\)
\(=\dfrac{-13}{6}-\dfrac{-7}{8}\)
\(=\dfrac{-31}{24}\)
