a: \(\dfrac{5}{11}-\dfrac{1}{2}+\dfrac{2}{5}+\dfrac{6}{11}+\dfrac{15}{25}+\dfrac{3}{4}+\dfrac{5}{16}\)
\(=\left(\dfrac{5}{11}+\dfrac{6}{11}\right)+\left(-\dfrac{1}{2}+\dfrac{3}{4}+\dfrac{5}{16}\right)+\left(\dfrac{2}{5}+\dfrac{3}{5}\right)\)
\(=1+1+\dfrac{-8+12+5}{16}\)
\(=2+\dfrac{9}{16}=\dfrac{41}{16}\)
b: \(\dfrac{9}{4}\cdot\dfrac{2}{5}-\left(\dfrac{3}{5}+\dfrac{3}{7}\right)\cdot\dfrac{12}{10}\)
\(=\dfrac{9}{10}-\dfrac{3\cdot7+3\cdot5}{35}\cdot\dfrac{12}{10}\)
\(=\dfrac{9}{10}-\dfrac{3\cdot12}{35}\cdot\dfrac{12}{10}\)
\(=\dfrac{9}{10}-\dfrac{432}{350}=\dfrac{9\cdot35-432}{350}=-\dfrac{117}{350}\)
c: \(\dfrac{7}{3}\cdot0,75-\left(\dfrac{7}{20}+30\%\right):\dfrac{3}{7}\)
\(=\dfrac{7}{3}\cdot\dfrac{3}{4}-\left(0,35+0,3\right)\cdot\dfrac{7}{3}\)
\(=\dfrac{7}{3}\left(0,75-0,65\right)=\dfrac{7}{3}\cdot\left(0,1\right)=\dfrac{7}{3}\cdot\dfrac{1}{10}=\dfrac{7}{30}\)
d: \(50\cdot3,02+1,98\cdot23+1,98\cdot27\)
\(=50\cdot3,02+1,98\cdot\left(23+27\right)\)
\(=50\cdot3,02+1,98\cdot50\)
\(=50\left(3,02+1,98\right)=50\cdot5=250\)
