$$\lim_{x,y\to0,0}\frac{\left(y^2-x\right)^2}{x^2+y^2}$$

$$\int\left(\frac{2}{9-x^2}\right)dx$$

$$\lim_{x\to-1}\left(\frac{5x^4+7x^3+4x+6}{x+1}\right)$$

$$-120-\left(-64-7\right)$$

$$\frac{d}{dx}\left(\sin\left(x+y\right)^2=y\right)$$

$$1x^2+12x+c$$