\(\dfrac{4}{19}\cdot-\dfrac{3}{7}+-\dfrac{3}{7}\cdot\dfrac{15}{19}+\dfrac{5}{7}\)
\(=-\dfrac{3}{7}\cdot\left(\dfrac{4}{19}+\dfrac{15}{19}\right)+\dfrac{5}{7}\)
\(=-\dfrac{3}{7}\cdot\dfrac{19}{19}+\dfrac{5}{7}\)
\(=-\dfrac{3}{7}+\dfrac{5}{7}\)
\(=\dfrac{-3+5}{7}\)
\(=\dfrac{2}{7}\)
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=-3/7(4/19+5/19)+5/7
=5/7-3/7=2/7
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