Ну блин ну ну решите кто нибудь

Решите задачу:

$\frac{9}{11} +(- \frac{2}{5} )=\frac{9}{11} -\frac{2}{5} = \frac{9*5-2*11}{5*11} = \frac{45-22}{55} = \frac{23}{45}$
$-8 \frac{9}{14} +3 \frac{3}{7} =- \frac{112+9}{14} + \frac{21+3}{7} =- \frac{121}{14} + \frac{24}{7} = \frac{-121+24*2}{14}= \frac{-64}{14} =-4 \frac{8}{14}$
$-6 \frac{11}{12} -8 \frac{13}{18} =-\frac{72+11}{12} - \frac{144+13}{18} = \\ =\frac{-83*6-157*4}{72}=- \frac{-498-628}{72} = \frac{-1126}{72} =- \frac{563}{36}= -15 \frac{23}{36}$
$-11 \frac{7}{9} + \frac{2}{15} =- \frac{99+7}{9} +\frac{2}{15}= \frac{-106*5+2*3}{45} = \frac{-530+6}{45} =- \frac{524}{45} =-11 \frac{29}{45}$
$3 \frac{6}{7} -6 \frac{4}{9} = \frac{21+6}{7} - \frac{54+4}{9} = \frac{27*9-58*7}{63} = \frac{243-371}{63} = \frac{-123}{63} =-1 \frac{60}{63} =-1 \frac{10}{11}$
$-3 \frac{8}{9} -2 \frac{1}{12} = -\frac{27+8}{9} - \frac{24+1}{12} = \frac{-35*4-25*3}{36} = \frac{-140-75}{36} = \frac{-215}{36} =-5 \frac{35}{36}$