18*. Simplify the fractions:
1) \(\frac{\left(x^{2}-x-5\right)\left(x^{2}-x-2\right)+2}{\left(x^{2}-x-5\right)\left(x^{2}-x-1\right)+4}\);
2) \(\frac{x+5-5 \sqrt{x-1}}{x-1-3 \sqrt{x-1}}\).
18. 1) \(\frac{x^{2}-x-4}{x^{2}-x-3}\). Hint. Use the following substitution: \(y=x^{2}-x-5\).
2) \(\frac{\sqrt{x-1}-2}{\sqrt{x-1}} \cdot\) Hint. Use the substitution: \(\sqrt{x-1}=y\)