$\frac{125-x^3}{5+x}$

$\left(+4\right)-\left(-16\right)$

$\cos\left(a\right)=\csc\left(a\right)\cdot\tan\left(a\right)\cdot\cos^3\left(a\right)$

$\log\left(u\right)-\log\left(9\right)=2$

$\cos^4\left(x\right)-\sin^4\left(x\right)-2cos^2\left(x\right)+1=0$

$\int15x\cdot csc^2xdx$

$-b\sqrt{\frac{b^2-4ac}{2a}}$