$\left[14x+3\right]<15$

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

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

$-8ab-7ab-1$

$x^{2}-xy+3y^{2};\text{para}x=4;y=2$

$\frac{d}{dx}\frac{e^{-2x}}{x^2}$

$\int\frac{\left(6x^2+50\right)}{\left(x+3\right)\left(x^2+4\right)}dx$