We have learned that, in in an algebraic expression, letters can stand for numbers. When we substitute a specific value for each variable, and then perform the operations, it's called evaluating the expression.

Let's evaluate the expression 3y + 2y when 5 = y.

Click on the steps to see how it's done.

                    

 

1. Replace each letter with its assigned value.
   
   The first step: 3(5) + 2(5)
   
   (Use Parentheses!)

2. Perform the operations, to find the value of the expression.
   
   The second step:
   
   3(5) + 2(5) = 15 + 10 = 25