$\left(2x^4-8x^2y\right)^2$

$\left(a+1\right)\left(a-1\right)-2\left(a+1\right)$

$56+820+-50$

$\lim_{x\to-4}\left(\frac{256-x^4}{4+x}\right)$

$7x^2\cdot7$

$\lim_{x\to0}\left(\frac{\sqrt{x}\left(sin\left(x-1\right)^2\right)}{\left(x+1\right)^3\left(lnx\right)^2}\right)$

$\left(-12\right)\::\:\left(-6\right)$