A+2a

The expression "a + 2a" can be simplified by combining like terms. Since "a" and "2a" are both terms that contain the variable "a" raised to the same power (which is 1 in this case), you can add them together.

So, you combine the coefficients:

1a + 2a = (1+2)a = 3a

Therefore, a + 2a simplifies to 3a.