$\left(-25xy^2+4x^2y\right)\left(-25xy^2+4x^{2y}\right)$

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

$\left(t+5\right)^7$

$5x^3\cdot\:2x^4$

$\left(2x+5\right)\left(2x-y\right)$

$\lim_{u\to\frac{\pi}{4}}\left(sec^2u+csc^2u\right)$

$\frac{m^6+1}{m+1}$