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

$25y^2+10y+1$

$\frac{z^3-3z^2+7}{z+4}$

$8+3-14.2$

$\sqrt{7-7x^2}$

$\lim_{x\to\infty}\left(\frac{e^x}{x^2-3x+5}\right)$

$\frac{2\sin\left(a\right)+3}{2\tan\left(a\right)+3\sec\left(a\right)}=\cos\left(a\right)$