$\left(\frac{1}{4}a^{2}-\frac{5}{2}a\right)+\frac{1}{2}a$

$sen\left(x\right)+2=-\frac{1}{sen\:x}$

$2m^2n+2m^2+n+1$

$\int8x^7ln\left(x\right)dx$

$\left(x\:-1\right)\left(x\:-5\right)$

$1-2sin^2\left(\frac{\pi}{12}\right)$

$\left(\left(-\frac{2}{3}\right)\right)xy+\left(\frac{1}{7}x^3\right)\cdot\left(\left(-\frac{2}{3}\right)\right)xy+\left(\frac{1}{7}x^3\right)$