Evaluating an expression means either to solve the expressions or to simply it.
Solving an expression:
2 - (10 + 5)
A simply expression. After doing the math the answer comes out as -3.
2x + 3x
This is an algebraic expression. This means we have variables like x and y. In this case, we can only simplify it. Because we don't know what x is equal to.
Because they are like terms (which means they have the variable) we can add them to together.
2x + 3x = 5x
I hope this answer clears up any misunderstandings about expressions and over all helped you learn something! If you still need some help, don't hesitate to DM on Brainly! I wish you best of luck on your journey of math!
EDIT:
Now what if you have an expression like this:
5x + 5m where x=4 and m=8
In mathematics, something like 5x is the same difference as 5 * x. And x is just a placeholder for a number or for another variable.
And in this equation, x is equal to 4. So, we just replace x with 4.
Just to add some information to support Noah's answer.
They will ask you to evaluate the expression when they give you the number for each unknown letters. For example : let's say we have 3x + 5z + 2y They can ask you to evaluate it for x = 2, z=4, y=3 So now all you have to do is replace the numbers to the letters they belong to. Does that make since ?
