$x^2-4x-51$

$1-\sin^2\left(-x\right)=\cos^2\left(x\right)$

$\frac{6^n\left(x\right)^{2n}}{\left(n+3\right)^2}$

$\int\frac{x^4}{\left(x^2-x+1\right)\left(x^2+1\right)^2}dx$

$\csc\left(x\right)\cdot\left(\sin\left(x\right)+\sin\left(x\right)\cdot\tan\left(x\right)^2\right)=\sec\left(x\right)^2$

$16t^2-24t+9$

$13y^2-14y-6$