$\left(\frac{4^2y^8}{4^3y^2}\right)$

$\cos\left(4x\right)\sin\left(x\right)-\sin\left(4x\right)\cos\left(y\right)$

$16.2+16.2+x+3+x+3+x+3$

$\frac{dy}{dx}\left(8+6x=sin\left(xy^4\right)\right)$

$\frac{dy}{dx}=-\frac{sin2x}{cos3y}$

$\lim_{x\to7}\left(\frac{5\sqrt{4+3x}}{7-x}\right)$

$x^2-4x^2-21$