(1/5m-1/2n)(1/25㎡+1/10mn+1/4n²)

问题描述:

(1/5m-1/2n)(1/25㎡+1/10mn+1/4n²)

(1/5m-1/2n)(1/25㎡+1/10mn+1/4n²)
=(1/5m)³-(1/2n)³
=1/125m³-1/8n³