$\left(x-y\right)dx+xdy$

$5\left[-2-2\left(-4\right)\right]-3\left[2\left(-2\right)-4\left(-4\right)\right]$

$5-5e^{0.12x}$

$\left(\frac{2x^3}{4y^{-1}}\right)^2$

$a\:=\:-\:4\:;\:b\:=\:5;\:c\:=\:10-8\:a\:+\:9\:b\:+\:5\:c\:$

$cos\left(x+y\right)cos\left(y\right)+\:sin\left(x+y\right)sin\left(y\right)=cosx$

$\cos-a=\cos a$