125*25*128*5=125*25*(8*4*4)*5=(125*8)*(25*4)*(5*4)=1000*100*20=2000000
128=8X4X2X2125X25X128X5=（125X8）X（25X4）X（5X2）X2=2000000
=125x8x25X4x5x2x2=1000x100x10x2=2000000
＝125³＋125²×3
