$3x^3+30x+75$

$\left(\frac{5}{7}b-\frac{1}{7}c\right)^2$

$\lim_{x\to\infty}\left(\frac{x^7+2x^3}{x+1}\right)$

$-20\cos\left(x\right)+10=0$

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

$\sqrt{a}+2\sqrt{3b}-\sqrt{c}+3\sqrt{3b}$

$\left(\frac{1}{\cos\theta}-\tan\theta\right)^{2}=\frac{1-\sin\theta}{1+\sin\theta}$