Question

How to evaluate an algebraic expression?

Answer 1

to evaluate an algebraic expression, you let the variables take on values
for example:

to evaluate this expression:
2*x + 3

you can let x=2 and plug it in:
2 *(2) + 3
4 + 3
=7

you can evaluate if you know what value to make the variables

Answer 2

PEMDAS

Parenthesis... Exponents... Multiplication and Division... Addition and Subtraction

First, solve what is in Parenthesis.
Next, solve what has Exponents.
Next, solve anything dealing with Multiplication and Division.
Lastly, solve anything dealing with Addition or Subtraction.