$\frac{dy}{dx}\left(\cos\left(9x+90y\right)\right)$

$\frac{3\left(y+3\right)}{y+1}+2$

$sec\left(x\right)-\left(tan\left(x\right)\cdot\left(sin\left(x\right)\right)\right)=cos\left(x\right)$

$6x\left(6x-y\right)-2\left(-y\right)$

$b^{\frac{3}{4}}+b^{-\frac{1}{3}}$

$-1z^2-7z^2+5z^2-3z^2$

$\sqrt{98.9}$