$\left(5x^4-3x^2\right)\left(3x^2-6\right)$

$4y\left(a+b\right)-3\left(a+b\right)$

$8.31-5.134$

$\left(\frac{3}{4}x+\frac{1}{2}\right)\left(\frac{3}{4}x-\frac{1}{2}\right)$

$\frac{-1}{30}x^2+\frac{5}{4}x\:-\:\sqrt{5}$

$23.04\cdot35.76$

$\lim_{x\to\infty}\left(\frac{2x^3}{e^{5x}}\right)$