$\lim_{x\to0}\left(\frac{\sqrt{1+9x}-\sqrt{1-10x}}{2}\right)$

$-2x-3\left(2x-3\right)$

$\int_0^{\infty\:}\left(\frac{1}{\left(1+x\right)^2}\right)dx$

$5\cdot4+6$

$\int\frac{x^3+2x^2+1}{x\left(x+2\right)^3}dx$

$0.2\left(-3\right)^2-3.5\left(-2\right)$

$\int\left(r^2+z^2\right)^{\frac{3}{2}}dz$