a, 2 x 31 x 12 + 4 x 6 x 42 + 8 x 27 x 3
=( 2 x 12 ) x 31 + ( 4 x 6 ) x 42 + ( 8 x 3 ) x 27=24 x 31 + 24 x 42 + 24 x 27=24 x ( 31 + 42 + 27 )=24 x 100=2400b,36 x 28 + 36 x 82 + 64 x 69 + 64 x 41=36 x ( 28 + 82 ) + 64 x ( 69 + 41 )=36 x 110 + 64 x 110=( 36 + 64 ) x 110=100 x 110=11000