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

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

$6:2+8.4-\:\left(3+2+1\right).5$

$x^2-55x+254$

$\frac{24}{5+3}\cdot5$

$\left(-14\right)-3-\left(-8\right)$

$144\:x^4\:+\:9\:y^4\:-\:36\:x^2\:y^2\:$