The expression 2 + 3(x + 3) + x is simplified correctly in the correct order. Which of these steps has an incorrect justification?

Answer:
c. is incorrect
Step-by-step explanation:
2 + 3(x + 3) + x
use the Distributive property a(b + c) = ab + ac
= 2 + 3x + 9 + x a. is correct
use the Commutative property of addition: a + b = b + a
= 2 + 9 + 3x + x addition
= (2 + 9) + 3x + x
= 11 + 3x + x b. is correct
use the Distributive property a(b + c) = ab + ac
not Associative property (a + b) + c = a + (b + c)
= 11 + (3 + 1)x c. is incorrect
= 11 + 4x
use the Commutative property of addition: a + b = b + a
= 4x + 11