B = $\frac{2}{17}$ + $\frac{15}{23}$ + $\frac{15}{17}$ + $\frac{-3}{19}$ +
$\frac{8}{23}$
B = $\frac{2}{17}$ + $\frac{15}{17}$ + $\frac{15}{23}$+ $\frac{8}{23}$+ $\frac{-3}{19}$
B = $\frac{17}{17}$ + $\frac{23}{23}$ + $\frac{-3}{19}$
B = 1 + 1 + $\frac{-3}{19}$
B = 2 + $\frac{-3}{19}$
B = $\frac{38}{19}$ + $\frac{-3}{19}$
B = $\frac{35}{19}$
D =(-20% + $\frac{3}{7}$ ) : $\frac{2}{11}$ + (-0,8 + $\frac{4}{7}$) : $\frac{2}{11}$
D =($\frac{-1}{5}$ + $\frac{3}{7}$ + $\frac{-8}{10}$ + $\frac{4}{7}$) . $\frac{11}{2}$
D =( $\frac{3}{7}$ + $\frac{4}{7}$ + $\frac{-2}{10}$ + $\frac{-8}{10}$). $\frac{11}{2}$
D =[ 1 + (-1) ] . $\frac{11}{2}$
D = 0 . $\frac{11}{2}$
D = 0
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