$5x^2-30x+45$

$\left(\left(-3\cdot8\right)-\left(-3\cdot8\right)\right)+9$

$\frac{1}{\csc^2x\tan\left(x\right)}+\frac{1}{\sec^2x\tan\left(x\right)}$

$4\left(-b-6\right)$

$\log\left(2^x+3\right)-2\left(\log\left(\frac{2^x-1}{2}\right)\right)-\log\left(2\right)$

$y=x^2+\frac{16}{x}$

$\frac{dy}{dx}\sec\left(6x\right)=\frac{3}{y}$