What does it mean to evaluate an expression in math?

Step-by-step explanation: To evaluate an expression means simplifying it down to a number and usually you will be given variables to substitute in and evaluate.

For example, let's evaluate the expression 3y + 7 when y = 2.

We simply multiply 3 x 2 and add 7 or 3(2) + 7.

3 x 2 is 6 so we have 6 + 7 which is 13.

i can't see the picture : /

english, cause i can’t you