Question

Answer 1

1.

\(a,\dfrac{3}{5}+\dfrac{-2}{5}=\dfrac{1}{5}\)

\(b,\left(\dfrac{4}{5}+\dfrac{1}{2}\right)\left(\dfrac{3}{13}-\dfrac{8}{13}\right)=\left(\dfrac{8}{10}+\dfrac{5}{10}\right).\left(-\dfrac{5}{13}\right)=\dfrac{13}{10}.\left(-\dfrac{5}{13}\right)=-\dfrac{1}{2}\)

\(c,\dfrac{-5}{7}\times\dfrac{2}{11}+-\dfrac{5}{7}\times\dfrac{9}{11}+1=-\dfrac{5}{7}\times\left(\dfrac{2}{11}+\dfrac{9}{11}\right)+1=-\dfrac{5}{7}+1=-\dfrac{5}{7}+\dfrac{7}{7}=\dfrac{2}{7}\)

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