解原式=5.5*4.4-44*0.33-0.44*22
=5.5*4.4-4.4*3.3-4.4*2.2
=4.4*(5.5-3.3-2.2)
=4.4*0
=0
(每项的第一个因数扩大或缩小几倍,则同项另一个因数则缩小或扩大几倍.)