解:∵B × A + C × B = B × (A+C)
∴5.5x8.2+1.8x5.5
= 5.5 × (8.2 + 1.8)
= (5×10 + 5)/10 × [(8×10 + 2)/10 + (1×10 + 8)/10]
= 55/10 × (82/10 + 18/10)
= 11/2 × 100/10
= 11/2 × 10
= 55
5.5x8.2+1.8x5.5
=5.5x(8.2+1.8)
=5.5x10
=55
5.5×8.2+1.8×5.5
=5.5×(8.2+1.8)
=5.5x10
=55
=(1.8+8.2)*5.5
=10*5.5
=55
5.5(8.2+1.8)=55