Question

tính nhanh:\(\left(\frac{-3}{7}+\frac{5}{11}\right):\frac{4}{31}+\left(\frac{-4}{7}+\frac{6}{11}\right):\frac{4}{31}\)

Answer 1

\(\left(-\frac{3}{7}+\frac{5}{11}\right):\frac{4}{31}+\left(-\frac{4}{7}+\frac{6}{11}\right):\frac{4}{31}\)

\(=\left(-\frac{3}{7}+\frac{5}{11}\right)\cdot\frac{31}{4}+\left(-\frac{4}{7}+\frac{6}{11}\right)\cdot\frac{31}{4}\)

\(=-\frac{3}{7}\cdot\frac{31}{4}+\frac{5}{11}\cdot\frac{31}{4}-\frac{4}{7}\cdot\frac{31}{4}+\frac{6}{11}\cdot\frac{31}{4}\)

\(=\frac{31}{4}\cdot\left(-\frac{3}{7}-\frac{4}{7}+\frac{5}{11}+\frac{6}{11}\right)\)

\(=\frac{31}{4}\cdot\left(-1+1\right)\)

\(=\frac{31}{4}\cdot0\)

\(=0\)