$x^2+x^2-84$

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

$\left(2x''\right)\left(x+3\right)$

$\frac{2}{5}=\frac{2}{x}$

$\sin x\cos x=\frac{3}{4}\cos x$

$\frac{dy}{dx}\left(sin2x\right)^{3x}$

$\left(5+2i\right)\cdot\left(-5-i\right)$