$15,3+72,850+1,0004+5,3$

$\frac{dy}{dx}=z\ln\left(\frac{a}{x}\right)x$

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

$\frac{5x^4-3x^2+2x+6}{\left(x-2\right)}$

$y-12>99$

$\int\frac{1}{b\left(1-b\right)}db$

$m2-13m+30$