$-\left(-7\right)\cdot\left(-5\right)\cdot\left(-3\right)\cdot\left(-2\right)$

$\int\sqrt{225-x^2}dx$

$\left(-7\right)-\left(-6\right)+\left(-2\right)-\left(-3\right)+\left(-10\right)$

$\lim_{x\to0}\left(\frac{x-\sin\left(x\right)}{\sin^2x}\right)$

$x\left(4x+10\right)$

$y'=1-x-y^2-xy^2$

$\int\frac{7x+3}{\left(7x^2+6x\right)^5}dx$