$\lim_{x\to2}\left(2\right)$

$\left(ax\right)^2+\left(by\right)^2=1$

$\int_{\sqrt{1.8^2-y^2}}^{\frac{-4}{27}y^2+3}\left(x\right)dx$

$\int\frac{\left(x^2-4\right)}{x\left(x^2+4\right)}dx$

$\int9x\left(3x+2\right)^3dx$

$\frac{dy}{dx}\left(4x\right)\left(\sqrt{3x^2+7}\right)$

$2+3x-x^2-3x^3x^4$