Question

What does it mean to evaluate an expression?

Answer 1

It means to solve, or simplify the expression.

Let's give two examples.

1) 5 + 2²
5 + 4
9 <- We are trying to simplify/solve the expression to as far as we can.
9 cannot be simplified, so the expression has been evaluated.

2) 4x - 5x + 9y
-x + 9y <- Can not be simplified any further so the expression has been evaluated via. combining like terms.

Answer 2

evaluate an expression means to simplifying an expression down to a numerical value