Answer
2 +3 and 2 + x are similar because they have the same constant; 2. And, the difference is that the equation: 2 + x, has a variable; the value of x is not identified.
Work Step by Step
2+3 and 2+x are similar because they have the same constant; 2. A constant is a number on its own (in this case). And, the difference is that the equation: 2+x, has a variable; the value of x is not identified, but the other equation, 2+3 has no variables.