$5a^2\cdot2a$

$\frac{64a^3-343}{4a+7}$

$\frac{\tan^2\left(52.5\right)-\tan^2\left(7.5\right)}{1-\tan^2\left(7.5\right)\cdot\tan^2\left(52.5\right)}$

$23-\left(-11+8-3\right)+\left(-7-10+24\right)$

$-x+y-3=0$

$\lim_{x\to\infty}\left(\frac{x^3+4x^2+4x}{x^2-4x}\right)$

$\frac{-2\sin\:^2\left(x\right)-2\sin\:\left(x\right)}{\left(1+\sin\:\left(x\right)\right)\cos\:\left(x\right)}$