Выполните действия -1 1/7*(4/5+19/20)*(6 5/6+4 2/3)

$1) \frac{4}{5} + \frac{19}{20} = \frac{16+19}{20} = \frac{35}{20} = \frac{7}{4} \\ 2)6 \frac{5}{6} +4 \frac{2}{3} =6+4+ \frac{5+4}{6} =10 \frac{9}{6} =11 \frac{1}{2} \\ 3)-1 \frac{1}{7} * \frac{7}{4} =- \frac{8}{7} * \frac{7}{4} =-2 \\ 4)-2*11 \frac{1}{2} =-2*11,5=-23$

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1)4/5+19/20=16/20+19/20=35/20=7/4
2)6 5/6+4 2/3=6 5/6+4 4/6=10 9/6=11 1/2
3)-1 1/7*7/4=-8/7*7/4=-2
4)-2*11 1/2=-2*11,5=-23