giúp e vs ạ e cần gấp lắm D= $\frac{1.2.3+2.4.6+3.6.9+5.10.15}{1.3.6+2.6.12+3.9.18+5.15.30}$

D= $\frac{1.2.3+2.4.6+3.6.9+5.10.15}{1.3.6+2.6.12+3.9.18+5.15.30}$

  = $\frac{1.2.3+2(1.2.3)+3(1.2.3)+5(1.2.3)}{1.3.6+2(1.3.6)+3(1.3.6)+5(1.3.6)}$

  = $\frac{(1.2.3).(1+2+3+5)}{(1.3.6).(1+2+3+5)}$

  = $\frac{1.2.3}{1.3.6}$

  = $\frac{1.2.3}{1.3.6}$

  = $\frac{2}{6}$

  = $\frac{1}{3}$