$$sin\left(4x\right)=-8cos^3xsin\left(-x\right)-4cos\left(-x\right)sinx$$

$$\sin2x=5\sin x$$

$$\frac{x^2+x+6}{x^2+4}$$

$$\frac{d^2}{dx^2}\left(x^2+2xe^{x+y}\right)$$

$$\left(5x^2-3\right)\left(5x^2+4\right)$$

$$\left(2x-12\right)\left(8x+1\right)$$

$$-4\left(3x-4v-1\right)$$