Question

\(A=\frac{3x5x7+6x10x14+9x15x21}{5x7x9+10x14x18+15x21x27}\)

Answer 1

\(A=\frac{1}{3}\)

Answer 2

\(\frac{3.5.7+6.10.14+9.15.21}{5.7.9+10.14.18+15.21.27}\)

= \(\frac{3.5.7+3.2.5.2.7.2+3.3.5.3.7.21}{5.7.9+5.2.7.2.9.2+5.3.7.3.9.3}\)

 = \(\frac{3.5.7+3.5.7.2.2.2+3.5.7.3.3.3}{5.7.9+5.7.9.2.2.2+5.7.9.3.3.3}\)

= \(\frac{3.5.7+3.5.7.8+3.5.7.27}{5.7.9+5.7.9.8+5.7.9.27}\)

= \(\frac{3.5.7.\left(1+8+27\right)}{5.7.9.\left(1+8+27\right)}\)

= \(\frac{3.5.7.36}{5.7.9.36}\)

= \(\frac{1}{3}\)

Answer 3

3.5.7 là sao