10mn÷(2n^3/5m)=10mn÷2n^3×5m
=25m^2n^(-2) 25倍乘以m的平方乘以n的-2次方
[(x^2-y^2)/xy]×[x/(-y)]=-(x^2-y^2)÷(xy)×x÷y
=(y^2-x^2)÷y^2
=1-x^2/x^2 1减去(x的平方与y的平方的商)
10mn÷(2n^3/5m)=10mn÷2n^3×5m
=25m^2n^(-2) 25倍乘以m的平方乘以n的-2次方
[(x^2-y^2)/xy]×[x/(-y)]=-(x^2-y^2)÷(xy)×x÷y
=(y^2-x^2)÷y^2
=1-x^2/x^2 1减去(x的平方与y的平方的商)