11 . 12 + 33 . 36 + 55 . 60
= 11 . 12 + 11 . 3 . 12 . 3 + 11 . 5 . 12 . 5
= (11 + 12) . 1 . (11 + 12) . 3 . (11 + 12) . 5
= 23 . 1 . 23 . 3 . 23 . 5
= 23 . (1 + 3 + 5)
= 23 . 9
= 207
\(11\cdot12+33\cdot36+55\cdot60\)
\(=11\cdot12+3\cdot11\cdot3\cdot12+5\cdot11\cdot5\cdot12\)
\(=11\cdot12\left(1+9+25\right)\)
\(=132\cdot35\)
\(=4620\)