Ответ:\(\frac{15a}{25a}=\frac{3}{5}\), при \(a\ne0\).\(\frac{33x^3}{26x^2}=\frac{33x}{26}\), при \(x\ne0\).\(\frac{a^2-b^2}{5a-5b}=\frac{(a-b)(a+b)}{5(a-b)}=\frac{a+b}{5}\), при \(a\ne b\).