How do you simplify the expression 4x + 2x?

To simplify the expression 4x + 2x, you combine like terms. In this case, both terms involve the variable x. The coefficients (the numbers in front of the variable) are 4 and 2.

Adding these coefficients together gives you 4 + 2 = 6. Since both terms are in the form of "x," you then write the result as 6x.

Thus, the simplified form of the expression 4x + 2x is 6x.