$$x e ^ { 2 y + 1 } + 1 - x = 0$$

$$4x+2\left(x-1\right)\le3\left(x+2\right)$$

$$\left(5x+10y\right)\:\left(5x-10y\right)\:$$

$$\arcsin\left(0.4\right)$$

$$\sin\left(x\right)=\cos\left(2x\right)+2$$

$$\lim_{x\to0}\left(\frac{1-cos\left(senx\right)}{tan^2x}\right)$$

$$49x^{2}-100$$