Question

Rút gọn :

\(\frac{2.6.12+6.12.20+12.21.32}{3.8.15+9.16.25+18.28.40}\)

Answer 1

\(\frac{2.6.12+6.12.20+12.21.32}{3.8.15+9.16.25+18.28.40}\)

\(=\frac{12.\left(12+120+672\right)}{3.\left(120+1200+6720\right)}\)

\(=\frac{12.\left(12+120+672\right)}{30\left(12+120+672\right)}\)

\(=\frac{12}{30}\)

\(=\frac{2}{5}\)

Answer 2

\(\frac{2.6.12+6.12.20+12.21.32}{3.8.15+9.16.25+18.28.40}\)

=\(\frac{2.6.12+6.12.2.10+12.3.7.4.8}{3.8.15+9.2.8.5.5+9.2.28.40}\)

=\(\frac{144+144.10+144.56}{360+360.10+360.56}\)

=\(\frac{144\left(1+10+56\right)}{360\left(1+10+56\right)}\)

=\(\frac{144.67}{360.67}\)

=\(\frac{72.2.67}{72.5.67}\)

=\(\frac{2}{5}\)