Lời giải:
\(\lim\limits_{x\to-\infty}\frac{\sqrt{25x^2-3x+1}}{3x+4}=\lim\limits_{x\to-\infty}\frac{\frac{\sqrt{25x^2-3x+1}}{\left(-x\right)}}{\frac{3x+4}{-x}}\)
\(=\lim\limits_{x\to-\infty}\frac{\sqrt{25-\frac{3}{x}+\frac{1}{x^2}}}{-3-\frac{4}{x}}=\frac{5}{-3}\)