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.
5(4) + 5m
Same this with m. The variable m is equal to 8.
5(4) + 5(8)
We can solve!
5(4) + 5(8) = 20 + 40 = 60
Our answer is 60.
