$\lim_{x\to7}\frac{4-x^2}{3-\sqrt{x^2+5}}$

$\left(7b+3a\right)\left(7b-11c\right)$

$5x-8<4+2x$

$x+1<-8$

$\frac{1}{1+\cos\left(x\right)}+\frac{1+\cos\left(x\right)}{\sin\left(x\right)^2}=2\csc\left(x\right)^2$

$\lim_{x\to0}\left(\frac{x^2}{\sqrt{16-x^2}-4}\right)$

$\int\left(x\cdot\left(4x+9\right)^{12}\right)dx$