$$v\left(x\right)=3.94\cdot x-0.125\cdot x^3$$

$$\int\left(12x+13\right)\ln\left(6x\right)dx$$

$$2a-7a-3a+7b-10a+9\:b$$

$$3m^2-3n^2+n+3m^2-7+4$$

$$\left(z\cdot z^2\right)$$

$$2\sqrt{144}$$