[tex]\it a)\ \ \dfrac{1}{18}+\dfrac{^{2)}1}{\ 9}+\dfrac{^{3)}1}{\ 6}=\dfrac{1+2+3}{18}=\dfrac{\ 6^{(3}}{18}=\dfrac{1}{3}\\ \\ \\ b)\ \ \dfrac{7}{36}-\dfrac{^{2)}1}{18}+\dfrac{^{9)}3}{4}=\dfrac{7-2+27}{36}=\dfrac{\ 32^{(4}}{36}=\dfrac{8}{9}\\ \\ \\ c)\ \ \dfrac{^{2)}37}{18}-\dfrac{^{9)}3}{4}-\dfrac{^{6)}5}{6}=\dfrac{74-27-30}{36}=\dfrac{17}{36}\\ \\ \\ d)\ \ \dfrac{11}{18}-\dfrac{^{2)}4}{9}-\dfrac{^{3)}5}{6}=\dfrac{11-8-15}{18}=\dfrac{18}{18}=1[/tex]
