Ответ:
- \(\frac{4a-4b}{10(a-b)}=\frac{4(a-b)}{10(a-b)}=\frac25\), при \(a\ne b\).
- \(\frac{a^2-18a+81}{a-9}=\frac{(a-9)^2}{a-9}=a-9\), при \(a\ne9\).
- \(\frac{8xy-16x}{16xy}=\frac{8x(y-2)}{16xy}=\frac{y-2}{2y}\), при \(x\ne0\), \(y\ne0\).
- \(\frac{x^2+14x+49}{x^2-49}=\frac{(x+7)^2}{(x-7)(x+7)}=\frac{x+7}{x-7}\), при \(x\ne7,-7\).
