答：m-n=a^5+b^5-a^2b^3-a^3b^2=a^5-a^3b^2+b^5-a^2b^3=a^3(a^2-b^2)-b^3(a^2-b^2)=(a^3-b^3)(a+b)(a-b)=(a-b)(a^2+ab+b^2)(a+b)(a-b)=(a+b)(a^2+ab+b^2)(a-b)^2因为a>0,b>0,所以a+b>0,a^2+ab+b^2>0.而(a-b)^2>=0,当...