Bài 3:
\(\dfrac{1}{2}-\left(\dfrac{1}{3}+\dfrac{3}{4}\right)\le x\le\dfrac{1}{24}-\left(\dfrac{1}{8}-\dfrac{1}{3}\right)\)
\(\Leftrightarrow\dfrac{-7}{12}\le x\le\dfrac{1}{4}\)
\(\Leftrightarrow\dfrac{-7}{12}\le\dfrac{12x}{12}\le\dfrac{3}{12}\)
\(\Leftrightarrow-7\le12x\le3\)
Mà \(x\in Z\)
\(\Rightarrow x\in\left\{0\right\}\)
\(1,\\ a,=\left(31\dfrac{6}{13}-36\dfrac{6}{13}\right)+5\dfrac{9}{41}=5\dfrac{9}{41}-5\dfrac{6}{13}=\dfrac{214}{41}-\dfrac{71}{13}=-\dfrac{129}{533}\\ b,=\dfrac{5}{3}-\dfrac{2}{7}+\dfrac{6}{5}=\dfrac{271}{105}\\ c,=\dfrac{1}{4}+\dfrac{3}{5}-\dfrac{1}{8}+\dfrac{2}{5}+\dfrac{5}{4}=\left(\dfrac{5}{4}+\dfrac{1}{4}\right)+\left(\dfrac{3}{5}+\dfrac{2}{5}\right)-\dfrac{1}{8}=\dfrac{3}{2}+1-\dfrac{1}{8}=\dfrac{19}{8}\\ d,=\left(8+6-3\right)-\left(\dfrac{9}{4}+\dfrac{5}{4}+\dfrac{2}{4}\right)+\left(\dfrac{2}{7}+\dfrac{3}{7}+\dfrac{9}{7}\right)=11-4+2=9\)
\(3,\\ \Rightarrow\dfrac{1}{2}-\dfrac{13}{12}\le x\le\dfrac{1}{24}+\dfrac{5}{24}\\ \Rightarrow-\dfrac{7}{12}\le x\le\dfrac{6}{24}=\dfrac{3}{12}\\ \Rightarrow x\in\left\{-\dfrac{7}{12};-\dfrac{1}{2};-\dfrac{5}{12};-\dfrac{1}{3};-\dfrac{1}{4};-\dfrac{1}{6};-\dfrac{1}{12};0;\dfrac{1}{12};\dfrac{1}{6};\dfrac{1}{4}\right\}\)
