6.4乘2.7+64乘0.73
=6.4×﹙2.7+7.3）
=6.4×10
=64是6.4和64。不是两个6.4啊6.4乘2.7+64乘0.73=6.4×2.7+6.4×10×0.73=6.4×2.7+6.4×7.3=6.4×﹙2.7+7.3）=6.4×10=64