$15x^2-8x+1$

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

$\left(a\sqrt[3]{a}-\sqrt[3]{\frac{1}{2}a}\right)\cdot\left|\left(\sqrt[2]{a}\right)^2+\sqrt[3]{a^{\frac{1}{5}}}\sqrt{a}\right|$

$\lim_{x\to0}\left(\frac{\ln\left|x\right|}{x}\right)$

$k2-25$

$8x+1=41$

$\left(2x^2+2xy\sin\left(\frac{y}{x}\right)\right)y=2y^2\sin\left(\frac{y}{x}\right)$