[tex]\bf \dfrac{7}{8}-\dfrac{3}{8}=\dfrac{7-3}{8}=\dfrac{\ 4^{(4}}{8}=\dfrac{1}{2}\\ \\ \\ \dfrac{5}{11}-\dfrac{2}{11}=\dfrac{5-2}{11}=\dfrac{3}{11}\\ \\ \\ \dfrac{9}{10}-\dfrac{3}{10}=\dfrac{\ \ 6^{(2}}{10}=\dfrac{3}{5}\\ \\ \\ \dfrac{109}{100}-\dfrac{59}{100}=\dfrac{109-59}{100}=\dfrac{\ \ 50^{(50}}{100}=\dfrac{1}{2}\\ \\ \\ \dfrac{18}{25}-\dfrac{12}{25}-\dfrac{1}{25}=\dfrac{\ \ 5^{(5}}{25}=\dfrac{1}{5}[/tex]
[tex]\bf \dfrac{40}{41}-\dfrac{15}{41}-\dfrac{12}{41}-\dfrac{11}{41}=\dfrac{40-15-12-11}{41}=\dfrac{2}{41}\\ \\ \\ \dfrac{100}{1000}-\dfrac{31}{1000}-\dfrac{64}{1000}-\dfrac{5}{1000}=\dfrac{100-31-64-5}{1000}=\dfrac{0}{1000}=0[/tex]
