Tìm lim (( căn 4n^2 - n +1)-n)/(căn 9n^2 +3n

Ta có:

lim4n2−n+1−n9n2+3n= limn4−1n+​  1n2−nn9+​ 3n =lim4−1n+1n2−19+3n=2−13=13

Chọn đáp án A