$\left(x^4\right)-\left(4x^2\right)+4=\left(x^2-2\right)^2$

$\int\frac{x-4}{x^2-x+\:2}dx$

$\:\left(5-8-9\right)+38-2\left[3+4-5\right]-1$

$x2-6x\ge-5\:$

$\int\left(\frac{y-1}{y\left(y+2\right)\left(y-2\right)}\right)dy$

$4x^2-9x^2-6x-1$

$+105-\left(468+1000-160\right)-\left(+2\right)$