$$125a^2+50a+5$$

$$5.5x\:+\:4\:=\:8x\:-\:19$$

$$\lim_{x\to\infty}\left(\frac{-e^{\left(2\cdot sqrt\left(2\right)\cdot x\right)}}{1-e^{\left(2\cdot sqrt\left(2\right)x\right)}}\right)$$

$$\frac{dy}{dx}=\frac{\left(x-y\right)}{\left(4\cdot x\right)}$$

$$18\:x-6\:x\:y^3$$

$$x^3-21x^2147x-343$$

$$\frac{d}{dx}\left(x^4\left(x^2+1\right)^6\right)$$