(1.2*3.6*10.8+2*6*18+13/1*13/3*13/9)/(1.2*2.4*4.8+2*4*8+13/1*13/2*13/4)
=(1.2*3.6*10.8+2*6*18+13/1*13/3*13/9)/[1.2*(3.6*2/3*10.8*4/9+2*(6*2/3)*(18*4/9)+13/1*(2/3*13/3)*(4/9*13/9)]
=(1.2*3.6*10.8+2*6*18+13/1*13/3*13/9)/{[(1.2*3.6*10.8+2*6*18+13/1*13/3*13/9)]*2/3*4/9}
=1/(2/3*4/9)
=27/8