9+8 is the commutative property
Answer: 9
Step-by-step explanation: so first you remove the ( ) because they’re useless in this then once you remove then Since two opposites add up to zero, remove them from the expression then you only get left with 9.
Step-by-step explanation:

15 - c = 6
15 - 6 = c
9 = c
c = 9
The answer is 12+k because sum means addition and it says 12 and k therefore you and 12 and k together and the algebraic expression would be 12+k
The same line! hope this helps! i’m not 100% sure so if i’m wrong don’t flame me