lim x->无穷 ((2x-1)^30(x-2)^5) / (2x+1)^35 分子分母同时除以x^35
=lim x->无穷[(2-1/x)^30*(1-2/x)^5]/(2+1/x)^35 x->无穷 1/x,2/x->0
=2^30*1^5/2^35=1/2^5=1/32