51=4x-x

To solve this equation, we'll need to combine like terms and isolate the variable.

Given equation: 51 = 4x - x

First, let's combine like terms on the right side of the equation: 51 = 3x

Now, let's isolate the variable x by dividing both sides of the equation by 3: 51/3 = 3x/3 17 = x

Therefore, the solution to the equation is x = 17.