bỏ dấu ngoặc:
a)\(\left(\dfrac{18}{25}+3\dfrac{5}{11}-\dfrac{6}{17}\right)-\left(2\dfrac{5}{11}-2\right)-\left(-\dfrac{7}{25}+\dfrac{11}{17}\right)\)
b)\(\left(5-\dfrac{9}{11}+\dfrac{4}{7}\right)-\left(2+\dfrac{2}{11}-\dfrac{3}{7}\right)\)
c)\(\left(7\dfrac{1}{2}+3\dfrac{5}{9}+\dfrac{1}{3}\right)-\left(6\dfrac{1}{2}-2\dfrac{5}{9}+\dfrac{1}{3}\right)\)
d)\(\left(\dfrac{1}{6}-\dfrac{3}{5}+\dfrac{4}{3}\right)-\left(\dfrac{1}{3}+\dfrac{2}{5}\right)+\left(3-\dfrac{1}{6}\right)\)
\(a,\dfrac{18}{25}+3\dfrac{5}{11}-\dfrac{6}{17}-2\dfrac{5}{11}+2-\dfrac{7}{25}-\dfrac{11}{17}\)
\(=\dfrac{18}{25}+\dfrac{38}{11}-\dfrac{6}{17}-\dfrac{27}{11}+2-\dfrac{7}{25}-\dfrac{11}{17}\)
\(=\left(\dfrac{18}{25}-\dfrac{7}{25}\right)+\left(\dfrac{38}{11}-\dfrac{27}{11}\right)-\left(\dfrac{6}{17}-\dfrac{11}{17}\right)+2\)
\(=\dfrac{11}{25}+1-\left(-\dfrac{5}{17}\right)+2\)
\(=\dfrac{11}{25}+1+\dfrac{5}{17}+2\)
\(=\dfrac{187}{425}+\dfrac{425}{425}+\dfrac{125}{425}+\dfrac{850}{425}=\dfrac{1587}{425}\)
\(b,5-\dfrac{9}{11}+\dfrac{4}{7}-2-\dfrac{2}{11}+\dfrac{3}{7}\)
\(=\left(5-2\right)-\left(\dfrac{9}{11}-\dfrac{2}{11}\right)+\left(\dfrac{4}{7}+\dfrac{3}{7}\right)\)
\(=3-\dfrac{7}{11}+1\)
\(=\left(3+1\right)-\dfrac{7}{11}\)
\(=4-\dfrac{7}{11}\)
\(=\dfrac{44}{11}-\dfrac{7}{11}=\dfrac{37}{11}\)
\(c,7\dfrac{1}{2}+3\dfrac{5}{9}+\dfrac{1}{3}-6\dfrac{1}{2}+2\dfrac{5}{2}-\dfrac{1}{3}\)
\(=\dfrac{15}{2}+\dfrac{32}{9}+\dfrac{1}{3}-\dfrac{13}{2}+\dfrac{9}{2}-\dfrac{1}{3}\)
\(=\left(\dfrac{15}{2}-\dfrac{13}{2}+\dfrac{9}{2}\right)+\left(\dfrac{1}{3}-\dfrac{1}{3}\right)+\dfrac{32}{9}\)
\(=\dfrac{11}{2}+1+\dfrac{32}{9}\)
\(=\dfrac{99}{18}+\dfrac{18}{18}+\dfrac{64}{18}=\dfrac{181}{18}\)
\(d,\dfrac{1}{6}-\dfrac{3}{5}+\dfrac{4}{3}-\dfrac{1}{3}-\dfrac{2}{5}+3-\dfrac{1}{6}\)
\(=\left(\dfrac{1}{6}-\dfrac{1}{6}\right)-\left(\dfrac{3}{5}-\dfrac{2}{5}\right)+\left(\dfrac{4}{3}-\dfrac{1}{3}\right)+3\)
\(=0-\dfrac{1}{5}+1+3\)
\(=\left(0+1+3\right)-\dfrac{1}{5}\)
\(=4-\dfrac{1}{5}\)
\(=\dfrac{20}{5}-\dfrac{1}{5}=\dfrac{19}{5}\)
