$f\left(x\right)=x^2\left(3\right)-x^2\left(2\right)-8x+12$

$13p^2-14p+8p^2$

$2x+6<-2$

$a-\left\{-\left(-2a+b\right)-2b-\left[3b+\left(-a+b\right)\right]+b\right\}$

$\frac{d}{dx}e^{x-y}=3+4y$

$\sqrt{\frac{x}{y}+\frac{4y}{x}}=2$

$\frac{\left(x^2-x-6\right)}{\frac{\left(2x+4\right)}{x}}$