$\frac{d^2}{dx^2}\left(\left(x^4+sec\left(x\right)\right)\right)$

$\frac{12-x}{x}=\frac{5}{7}$

$\int-\frac{2}{4-5x}dx$

$16,05+0,005+81,005+0,00005+0,000005$

$\int\frac{\left[\ln\:\left(x^2-2\right)\right]^5}{\left(x-2x^{-1}\right)}dx$

$\int\left(2e^2^x^{+1}\right)dx$

$x+2y+2x-2y-5y$