：x的m次方×＜（x的n次幂）的4次方＞/＜x的m+1次方×（2x的n-1次方)＞
=x^m[(x^n)^4]/[x^(m+1)*2x^(n-1)]
=x^m*x^(4n)/[2x^(m+n)]
=x^(m+4n)/[2x^(m+n)]
=(1/2)x^3n