$\lim_{x\to-1}\frac{\left(3x^2\right)}{\left(2x-1\right)}$

$\int7x^6\sin\left(x^7\right)dx$

$5z^2-2y^2+14+8x^2+9y^2-4z^2-x^2$

$\int\:\frac{1}{\sqrt[3]{5-3s}}\:ds$

$\int e^{-x}\left(e^{3x}-e^x-1\right)dx$

$x^2-6x+9<0$

$\frac{1}{\cos\left(a\right)}\csc\left(a\right)-\tan\left(a\right)=\cot a$