(1/5m-1/2n)(1/25m+1/10mn+1/4n)怎么化简?
问题描述:
(1/5m-1/2n)(1/25m+1/10mn+1/4n)怎么化简?
答
已知:a^3-b^3=(a+b)(a^2+ab+b^2) 令a=1/5m,b=1/2n 则原式==(a+b)(a^2+ab+b^2)=a^3-b^3=(1/5m)^3-(1/2n)^3