$$\lim_{x\to\infty}\frac{86x^2+5x}{\left(1-x\right)\left(2x-3\right)}$$

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

$$64\left(a+b\right)^2-144\left(a-b\right)^2$$

$$\left(2x^2+9\right)\left(2x^2+5\right)$$

$$36\cdot36$$

$$\frac{1}{3x+1}+\frac{1}{2x+2}+\frac{1}{x^2-1}$$

$$\frac{a^{18}}{a^6}$$