To solve the equation, we can combine like terms on both sides of the equation.

On the left side, we have 7x - x. This simplifies to 6x.

On the right side, we have 25 + 12 - 7. This simplifies to 30.

So the equation becomes 6x = 30.

To solve for x, we divide both sides of the equation by 6:

6x/6 = 30/6

This simplifies to x = 5.

Therefore, the solution to the equation is x = 5.