$9x^2+18x+81$

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

$x^2-10x+90$

$2.7307^2$

$10y^2-11y-6$

$\left(3x+5y\right)\left(3-5y\right)$

$\lim_{x\to\infty}\left(\frac{x\left(ln\left(4\right)\right)}{ln\left(x\right)}\right)$