$$2x^2+3=7x$$

$$\log_{10}\left(x\right)+4\log_{10}\left(x^2\right)$$

$$7h+1,\:si\:h=3$$

$$\sin\left(x\right)\frac{dy}{dx}+\cos\left(x\right)y=x\sin\left(x\right)y\left(\frac{\pi}{2}=2\right)$$

$$\frac{x^9-y^6}{x-y}$$

$$\:2cos\:x\:2cos^3\:x\:=\:sin\:x\:sin\:2x$$