55乘36怎样简?
于*** 2013-09-04 19:02:46 举报
36*(0.45+0.55)=36*1=36
0.36*7.5+0.036*25=0.36*7.5+0.36*2.5 =0.36*(7.5+2.5) =0.36*10 =3.6