$\sec^4\left(x\right)-2\sec^2\left(x\right)\cdot\tan^2\left(x\right)+\tan^4\left(x\right)$

$\left(+100\right)\::\left(-20\right)\:x\:2$

$\frac{x+1}{x-3}<2$

$\int te^{2t}dx$

$x^3dy-x^2ydx=0$

$-8\left(-10x\right)-4\left(6+9x\right)$

$\int\frac{x^2-4x+4}{x^3-4x^2+13x}dx$