Write a numerical expression that satisfies all of the following conditions. • The only number used in the expression is 3. At least one exponent other than 1 is used. When the expression is evaluated, the answer is greater than 30 and less than 40.​

To evaluate a variable expression means to find the value of the expression when the variable is (or variables are) replaced by a number (or numbers).

Here is a variable expression: 3x+7.

To evaluate this expression when x=2 mean to substitute 2 in place of x, and find the number (the value). [see note below]

3(2)+7=6+7=13.

When x=2, the expression has a value of `13.

If we evaluate the same expression when x=10, we get:

3(10)+7=30+7=37.

Here's a variable expression with two variables : 3x−2y

In order to evaluate this expression, we'll need values (numbers) for both x and y.

Evaluate the expression 3x−2y when x=4 and y=5

3(4)−2(5)=12−10=2

If we change the values to x=5 and y=4, we get

3(5)−2(4)=15−8=7.

Note:

To avoid saying exactly the same thing over and over, we use the following to mean the same thing:

evaluate the expression when x=2

evaluate the expression for x=2

evaluate the expression at x=2

evaluate the expression assuming x=2

evaluate the expression if x=2

Also

If there is only one variable in an expression, we don't always need to mention it:

evaluate the expression for 2

evaluate the expression at 2