Ну блин ну ну решите кто нибудь

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