What is 4x-x?

The expression 4x-x can be simplified using algebraic operations of combining like terms.

4x-x = (4-1)x = 3x

Therefore, the expression 4x - x is equivalent to 3x and represents a linear polynomial with a degree of 1. It has only one variable, x, and its coefficient is 3. The graph of the function y=3x is a straight line passing through the origin with a slope of 3.