9. Constants are the value that stays the same and cannot be changed, other words, it does not contain a variable.
In the equation, 15 does not have a variable.
Solution: B. 15
10. Perimeter is all the side lengths combined; add them all up.
(4x - 10) + (2x + 6) + 5x
Combine the like terms
11x - 4 units
Solution: H. (11x-4) units
