To evaluate the expression $15 - 4z$ for a given value of $z$, what is the very first step you should take?

Replace the variable z with its given value.

Understanding and Evaluating Expressions Practice — Grade 7 math

1. Evaluate the algebraic expression $8m - 6$ for $m = 5$. The value is ___.
2. What is the value of the expression $2x + 5y$ when $x = 4$ and $y = 3$?
- A. 23
- B. 39
- C. 14
- D. 49
3. A streaming service costs 8 dollars per month plus 3 dollars for each movie rental, $r$. The expression is $8 + 3r$. What is the cost for a month with 5 rentals?
- A. 16 dollars
- B. 23 dollars
- C. 43 dollars
- D. 55 dollars
4. Using the formula for the perimeter of a rectangle, $P = 2(l + w)$, find the perimeter when the length $l=10$ and the width $w=4$. The perimeter is ___.
5. To evaluate the expression $15 - 4z$ for a given value of $z$, what is the very first step you should take?
- A. Subtract 4 from 15.
- B. Multiply 4 by the value of z.
- C. Replace the variable z with its given value.
- D. Find the value of z.
6. What is the value of the expression $7y - 5$ when $y = 3$? The value is ___.
7. Evaluate the expression $8 + 4k$ for $k = 6$.
- A. 72
- B. 32
- C. 48
- D. 18
8. Find the value of the expression $2p + q$ if $p = 6$ and $q = 9$. The value is ___.
9. Renting a scooter costs 5 dollars plus 3 dollars per hour, $h$. The expression is $5 + 3h$. What is the total cost to rent the scooter for 4 hours?
- A. 17 dollars
- B. 32 dollars
- C. 12 dollars
- D. 23 dollars
10. Using the formula for the perimeter of a rectangle, $P = 2(l + w)$, find the value of $P$ when $l = 10$ and $w = 4$. The value of $P$ is ___.