$\frac{\left(30+4\right)}{\left(5\cdot4-3\right)}+\frac{\left(14-4\right)}{\left(8-6\right)}$

$x^2-40x+400=0$

$\lim_{x\to\infty}\left(\frac{\sin\left(9x\right)}{\sin\left(7x\right)}\right)$

$5a^2-6a+2a-4a^2$

$\int\:\frac{\left(\sqrt{x}-1\right)^2}{x^2}dx$

$-3x+6y-8$

$\left(+15\right)-\left(-7\right)+\left(-10\right)+\left(+13\right)$