Пажалуста помогите решить то что я обвела карандашом даю 26 баллов.....

Решите задачу:

$11) (3\frac{1}{3} )^2-(4\frac{1}{2} )^2=(3\frac{1}{3}-4\frac{1}{2})(3\frac{1}{3}+4\frac{1}{2})=(\frac{20}{6}-\frac{27}{6})(\frac{20}{6}+\frac{27}{6})=-\frac{7*47}{6*6} =-\frac{329}{36}\\ \\ 12)(5\frac{1}{6})^2-(7\frac{1}{3} )^2=(5\frac{1}{6}-7\frac{1}{3})(5\frac{1}{6}+7\frac{1}{3})=(\frac{31}{6}-\frac{44}{6})(\frac{31}{6}+\frac{44}{6})=-\frac{13*75}{6*6}=-\frac{325}{12} \\ \\ 13)51^2-41^2=(51-41)(51+41)=10*92=920\\ \\ 14)54^2-46^2=(54-46)(54+46)=8*100=800\\ \\ 15)76^2-24^2=(76+24)(76-24)=100*52=5200$

$16)328^2-172^2=(328-172)(328+172)=156*500=78000\\ \\ 17)(3\frac{2}{3})^2-(2\frac{1}{3})^2=(3\frac{2}{3}-2\frac{1}{3})(3\frac{2}{3}+2\frac{1}{3})=(\frac{11}{3}-\frac{7}{3})(\frac{11}{3}+\frac{7}{3})=\frac{4*18}{3*3}=8\\ \\ 18)(7\frac{5}{9})^2-(4\frac{4}{9})^2=(7\frac{5}{9}-4\frac{4}{9})(7\frac{5}{9}+4\frac{4}{9})=(\frac{68}{9}-\frac{40}{9})(\frac{68}{9}+\frac{40}{9})=\frac{28*108}{9*9}=\frac{112}{3}$