51=4x-x

To solve the equation 51 = 4x - x, we can simplify it by combining like terms.

On the right side, 4x - x is equal to 3x.

So the equation becomes 51 = 3x.

To isolate x, we divide both sides of the equation by 3:

51 / 3 = 3x / 3.

This simplifies to 17 = x.

Therefore, the solution to the equation 51 = 4x - x is x = 17.