$\int sin^4tcos^4tdt$

$\left(7z+9x\right)\left(7z-9x\right)$

$\left(3t^2+5t+6\right)-\left(t^2+7t+4\right)$

$\left(csc\left(x\right)+cot\left(x\right)\right)^2=cot\left(\frac{t}{2}\right)^2$

$\frac{x^3-1}{x^2-1}$

$-54\::\:\:x\:\:=\:-9$

$\lim_{x\to\infty}\left(\frac{x^2+4}{x^2}\right)^{\left(x-1\right)\left(x+1\right)}$