$$\frac{2x^4-7x^3+9}{x^2+3}$$

$$\int_{20}^{\infty}\frac{10\cdot sin\left(x\right)}{x}dx$$

$$\int\frac{9x-2x^2+4}{\left(x-3\right)\left(x^2+4\right)}dx$$

$$\frac{1}{tanx\left(1+\cos\left(2x\right)\right)}=\csc\left(2x\right)$$

$$2y-1>5$$

$$-3.5\left(4x-3\right)$$