How do i evaluate an expression for the variable?

To evaluate an algebraic expression, you have to substitute a number for each variable. If the value of the variables are known, you can replace them and then evaluate the expression.

Step-by-step explanation:

1/3 + 1/3 ≠ 2/6 because 1/3 alone = 2/6  

step by step explanation:

1/3 + 1/3 = 2/3       2/3=4/6