4.5x5.5+5.5x5.5=5.5x(4.5+5.5)=5.5x10=55
=5.5(4.5+5.5)=5.5*10=55
4.5×5.5+5.5×5.5=(4.5+5.5)×5.5=10×5.5=55
=(4.5+5.5)*5.5=10*5.5=55