$\lim_{x,y\to0,0}\left(\frac{16y^2+40yx^2+25x^4}{4y+5x^2}\right)$

$13\sqrt{3}-\:8\sqrt{3}-\:4\sqrt{3}+\:10\sqrt{3}+7\sqrt{3}$

$-2\cdot\left(+4\right)\cdot\left(+5\right)$

$\left(x+y\right)^2-\left(b+w\right)^2$

$-x+2y-6x+10y$

$\lim_{x\to\infty}\left(\sqrt{x}\left(\sqrt{x+3}-\sqrt{x-2}\right)\right)$

$0.0672\cdot0.09854$