Question

what can be added to $3x + 1$ without changing the value of the expression?
2
3
1
0

Explanation:

Step1: Recall additive identity property

The additive identity property states that for any number \( a \), \( a + 0=a \). So, adding 0 to an expression does not change its value.

Step2: Apply to the given expression

For the expression \( 3x + 1 \), if we add 0 to it, we get \( (3x + 1)+0=3x + 1 \), which is the same as the original expression. Adding 2, 3, or 1 would change the value (e.g., \( 3x + 1+2 = 3x+3 \), \( 3x + 1+3=3x + 4 \), \( 3x + 1+1=3x + 2 \), all different from \( 3x + 1 \)).

Answer:

0 (the option corresponding to 0)