$$\lim_{x\to0}\left(\frac{x+sin\left(2x\right)}{x^2}\right)$$

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

$$a+b-c-b-c-2c-a$$

$$\left(3^2\cdot3^2\right)^4$$

$$x^2+7x+9$$

$$\left(7x-2\right)\left(7x+4\right)$$

$$5y+2\left(y+4\right)+4$$