$x^2+2x<1$

$\lim_{x\to0}\left(\frac{\tan\left(7x\right)}{\tan\left(3t\right)}\right)$

$\lim_{x\to0}\left(\frac{3.35x-\sin\left(67\right)x}{3.35\left(1-\cos\left(67\right)x\right)}\right)$

$c^2-2c-3=0$

$1-\cos\left(2a\right)+\sin\left(2a\right)$

$40+30-10$

$\left(c^2+3d\right)^2$