$\left(-8x\right)\cdot\left(2xy\right)$

$5\sqrt{a^7}+2\sqrt{a^5}+4\sqrt{a^2}$

$\frac{\left(\left(-1^n\left(x+7\right)^n\right)\right)}{\left(4^{n+1}\right)}$

$x^3=y^2$

$\int_0^4\left(64-x^2\right)^{-2}dx$

$12\sin^2\left(x\right)-\sin\left(x\right)-1=0$

$\frac{\sin c}{\left(1+\cos c\right)}=\frac{\left(1-\cos c\right)}{\sin c}$