$x^4+40x^2+25$

$9-\left|8-4\left(7-5\right)\right|$

$\left(x\cdot\frac{dy}{dx}+y\right)\cdot\sqrt{1+x^2}=x$

$\left(3x^2y^4\right)^3\cdot2x^2y^2$

$\frac{d}{dx}\:\sqrt{\frac{1-x}{1+x}}$

$k\cdot cos\left(v\right)\cdot\left(\left(b+k\cdot cos\left(v\right)\right)\cdot sin\left(u\right)\right)$

$\left(3x^2+6x\right)\left(x^2+3x+5\right)$