$$ydy-4xdx=0$$

$$\frac{1a^{8}-100b^{8}}{9a^{3}+10b^{4}}$$

$$\frac{120}{3}$$

$$25x^6+10x^2+35x$$

$$\lim_{x\to1}\left(\frac{cos\left(2x\right)-\cos\left(x\right)}{x-1}\right)$$

$$726+432-39$$