$$3m+9$$

$$2x^2.2x^2$$

$$\int\frac{\left(x+1\right)}{x^2\left(x^2+9\right)}dx$$

$$6a^2b^3c+4ab^2c^3-2a^2c^2+\:a^2b^2c^2$$

$$\left(\frac{x^2y^{-1}+x^{-1}y^2}{x^{-1}+y^{-1}}\right)$$

$$-2+8\cdot9$$

$$\cot\left(x\right)-\tan\left(x\right)\csc^2\left(x\right)=-\sec\left(x\right)\sin\left(x\right)$$