In algebra we work with variables and numerals. To evaluate an algebraic expression simply means that you are going to determine the value of an expression by substituting and evaluating using the operation order.
in summary in order to evaluate an algebraic expression
you must identify the variable and its value
you will substitute the given value for the variable
complete the necessary calculations
Take for example;
evaluate 2a + 4b - 2c
given that a = 2 , b = 1 , c = 5
since you already know the value of the variables you substitute them into the question
1:15 pm + 5 minutes =1:20 PM You add 5 minutes because your watch is slow then subtract 3 minutes because you thought the watch was 3 minutes fast. real time is 1:17 PM 1:20 pm - 3 minutes = 1:17 PM