lim x → 2 4 x + 1 − 3 x 2 − 4 = lim x → 2 ( 4 x + 1 − 3 ) ( 4 x + 1 + 3 ) ( x 2 − 4 ) ( 4 x + 1 + 3 ) = lim x → 2 4 x + 1 − 9 ( x 2 − 4 ) ( 4 x + 1 + 3 ) = lim x → 2 4 x − 8 ( x 2 − 4 ) ( 4 x + 1 + 3 ) = lim x → 2 4 ( x + 2 ) ( 4 x + 1 + 3 ) = 1 6
Chọn đáp án B