$-8x^{-4}y^{-2}\cdot4x^4y^{-3}\cdot7x^{-4}$

$\lim_{x\to\infty}\left(\frac{e^{\left(3x\right)}}{x^6}\right)$

$\int3\sec^3\left(5x\right)dx$

$\left(b+3a\right)^4$

$10\cdot a\cdot\sqrt{3\cdot a}+\frac{40a}{2}\cdot\sqrt{3a}-\frac{25}{a}\cdot a^2\cdot\sqrt{3a}$

$\frac{1}{25}x^2\cdot\frac{9}{16}y^2$

$8y^3+27m^3$