$$4\sqrt{x}\left(e^x+1\right)$$

$$2xb+8x^2b^2+6x^2b$$

$$\left(8-5x^2\right)^3$$

$$y^2+y+1=0$$

$$\left(cos\left(x\right)cos\left(y\right)+cot\left(x\right)\right)dx-sin\left(x\right)sin\left(y\right)dy=0$$

$$\int_4^xe^{3u}du$$

$$u^2-18u+81$$