$$3x-7+2x+1$$

$$\lim_{x\to0}\left(\frac{x^2-5x}{x^2-x}\right)$$

$$1-\sin\left(\infty\right)\cdot\cos\left(\infty\right)\cdot\tan\left(\infty\right)=\cos\left(\infty\right)^2$$

$$6\cos^2\left(x\right)-3=3-6\sin^2\left(x\right)$$

$$\frac{3}{8}\sqrt{108m^5n^{10}f^{15}}$$

$$x^3-12x-16$$

$$3n^2-75$$