$$25x^2+200x+400$$

$$\frac{\sin2\left(x\right)}{1-\sin^2\left(x\right)}=2\tan\left(x\right)$$

$$\frac{dv}{dt}=\frac{3+v^2}{v}$$

$$\lim_{x\to\infty}\left(\frac{1}{x^2+3}\right)$$

$$6y\:\left(2x\:-\:5\right)\:$$

$$x^3-18x^2+81x$$

$$\frac{d^2}{dx^2}\left(5y-7x\right)$$