Tính a) 4x9x10 / 9x10x8 b) 7x5x14 / 14x7x6

a) \(\frac{{4 \times 9 \times 10}}{{9 \times 10 \times 8}}\)

= \(\frac{{4 \times \not 9 \times \not 1\not 0}}{{\not 9 \times \not 1\not 0 \times 8}} = \frac{4}{8} = \frac{1}{2}\)

b) \(\frac{{7 \times 5 \times 14}}{{14 \times 7 \times 6}}\)

= \(\frac{{\not 7 \times 5 \times \not 1\not 4}}{{\not 1\not 4 \times \not 7 \times 6}} = \frac{5}{6}\)