$\left(a+30\right)\left(a-4\right)$

$\int x\cdot\ln\left(\frac{1-x}{x+1}\right)dx$

$3\ln\left(x^2\right)-2\ln\left(x^3\right)$

$\frac{\sin\:^2\left(x\right)}{1-\cos\:\left(x\right)}=1+\cos\:\left(x\right)$

$\left(-5a^2x+2by^2\right)^3$

$-13\left(10n\:-\:7\right)\:+\:6n$

$15,3+72,850+1,0004+5,3$