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Решите задачу:

$\frac{6}{12}*\frac{3}{8} = \frac{12*9}{24} = \frac{108}{24}=4,5$

$\frac{5}{6} :\frac{9}{10} =\frac{5}{6} *\frac{9}{10} =\frac{25*27}{30} =\frac{675}{30} = 22,5$

$\frac{5}{9} *\frac{6}{7} = \frac{35*54}{63} =\frac{1890}{63} =30$

$-\frac{10}{11} :\frac{4}{5} =-\frac{10}{11} *\frac{5}{4} = -\frac{4*55}{44} =-\frac{220}{44} =-5$

$-\frac{5}{9} +(-6\frac{5}{9} )=-(6\frac{5}{9}+\frac{5}{9})=-6\frac{10}{9}=-7\frac{1}{9}$

$\frac{46}{35} +(-2\frac{23}{35})=\frac{46}{35} -\frac{2*35+23}{35} =\frac{46}{35} -\frac{93}{35} =\frac{46-93}{35} =-\frac{47}{35} =-1\frac{12}{35}$

$-\frac{45}{376} +\frac{40}{47} =-\frac{45}{376} +\frac{40*8}{376} =\frac{-45+320}{376}=\frac{275}{376}$

$-\frac{565}{2507} +\frac{844}{2507} =\frac{844-565}{2507}=\frac{279}{2507}$