$-2.5-\frac{2}{5}$

$\lim_{x\to0}\left(\frac{x^2+280x}{7\cdot sin\left(x\right)}\right)$

$2\sin^2\left(b\right)+3\sin\left(b\right)-5$

$\left(-5\right)\left(9\right)$

$\left(r-1\right)\left(r-1\right)\left(r-1\right)$

$\int\left(-e^x\right)sec^2\left(x\right)dx$

$\frac{dy}{dx}+xy=2x$