$12xy^2mzx\cdot2y^3mz$

$\frac{d^2}{dx^2}\left(x^2+6xy-2y^2=3\right)$

$\int_2^{\infty}\left(\cos\left(\pi\cdot x\right)\right)dx$

$\lim_{x\to-7}\left(\frac{4x^4+5x^3+5x+6}{x+1}\right)$

$y=\frac{x^4}{4}+\frac{5}{9}x^3-x^2+9x-4$

$\frac{x-3}{x}\ge x+2$

$\tan^2x\csc^2x-3=0$