$4.25\cdot\left(-1.25\right)$

$\frac{1}{1+x^5}$

$\frac{m^2}{64}-\frac{27n^6}{125}$

$100x^2+24x-8\:-\:117x^2$

$y=\frac{\left(x^2-5\right)^{\frac{1}{9}\sqrt{x^3+4}}}{x^6+6x+3}$

$\frac{\csc\left(x\right)}{1+csc\left(x\right)}-\frac{1}{sen\left(x\right)-1}=2sec^2\left(x\right)$

$\sqrt{-89}$