$$\frac{cos(2x)}{cos(x)} + sin(x) = \frac{cos^2(x) - sin^2(x)}{cos(x)} + sin(x) = \frac{cos^2(x)}{cos(x)} - \frac{sin^2(x)}{cos(x)} + sin(x) = cos(x) - \frac{sin^2(x)}{cos(x)} + sin(x) = cos(x) - \frac{sin^2(x) - sin(x)cos(x)}{cos(x)} = cos(x) - \frac{sin(x)(sin(x) - cos(x))}{cos(x)}$$
$$\textbf{Ответ: } cos(x) + sin(x) - \frac{sin^2(x)}{cos(x)}$$