$\frac{\infty}{\infty^2}$

$-755\cdot\left(3-6\right)$

$\left(6a^3-7b^4\right)^2$

$\sqrt{\left(-3\right)}^2\cdot\left(-3\right)$

$16+40x^2+25x^2$

$\cos\left(x\right)\sec\left(x\right)-\sin^2\left(x\right)$

$\lim_{x\to-\infty}\:ln\left(x^2+1\right)-\frac{2}{\left(x+1\right)}$