Engineering Mathematics - Limits

The value of $\lim_{x\to\infty} (x - \sqrt{x^2 + x})$ is equal to

Consider the limit: $\lim_{x\to 1} \left(\frac{1}{\ln x} - \frac{1}{x-1}\right)$ The limit (correct up to one decimal place) is _________

The value of $\lim_{x\to\infty} \frac{x^2-5x+4}{4x^2+2x}$ is