Question

[Nguyễn Ánh Tuyết]

1 

a . 21 |11 * 22 |17 * 68 |63 .

b . 5 | 14 * 7 | 13 * 26 | 25 .

Answer 1

[Thảo Nguyễn『緑』]

a) \(\frac{21}{11}\cdot\frac{22}{17}\cdot\frac{68}{63}\)

\(=\frac{21\cdot22\cdot68}{11\cdot17\cdot63}\)

\(=\frac{3\cdot7\cdot2\cdot11\cdot4\cdot17}{11\cdot17\cdot7\cdot3\cdot3}\)

\(=\frac{2\cdot4}{3}\)

\(=\frac{8}{3}\)

b) \(\frac{5}{14}\cdot\frac{7}{13}\cdot\frac{26}{25}\)

\(=\frac{5\cdot7\cdot26}{14\cdot13\cdot25}\)

\(=\frac{5\cdot7\cdot2\cdot13}{2\cdot7\cdot13\cdot5\cdot5}\)

\(=\frac{1}{5}\)

=))