$$\int\frac{1}{\sqrt{36x^2+1}}dx$$

$$\left(a-\:b\right)\:2\:-\:18\:\left(a\:-\:b\right)\:+\:81\:$$

$$\left(4y-1\right)\left(4y+7\right)$$

$$\frac{dy}{dx}-11x^3y=0$$

$$\frac{dy}{dx}-y=\cos\left(e^{-x}\right)$$

$$5\left(-8v+4\right)+5v$$