$9x^2-18x=7$

$\left(m-n+t\right)^2$

$\frac{dy}{dx}=\frac{-2xcos^2y}{\left(1+x^2\right)^2}$

$\left(x+4\right)\left(x-4\right)+.\left(x+5\right)\left(x-5\right)-2\left(x+3\right)\left(x-3\right)$

$y\sec^2x\frac{dy}{dx}=y^2+1$

$5x^2+45x+90$

$\lim_{x\to0}\left(1+3x\right)^{\frac{4}{x}}$