$x^{7x}=y$

$25^6\cdot25^3$

$y^2+14y-24$

$\lim_{y\to-2}\left(\frac{y+2}{\sqrt{y+3}-1}\right)$

$-\left(-14\right)-\left(-7\right)+\left(-13\right)+2$

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

$1+\sec\left(x\right)-\sin\left(x\right)\sin\left(x\right)\sec\left(x\right)$