Question

the movement of the progress bar may be uneven because questions can be worth more or less (including zero) depending on your answe
which property is not used to simplify the following expression?
2·(x + 5) + 7x = (2x + 10) + 7x
= (10 + 2x) + 7x
= 10 + (2x + 7x)
= 10 + 9x
= 9x + 10

communtative property of addition

distributive property

communtative property of multiplication

associative property of addition

Explanation:

Step1: Analyze each property

• Distributive Property: Used in \(2\cdot(x + 5)=(2x + 10)\) (distributing 2 over \(x+5\)).
• Commutative Property of Addition: Used in \((2x + 10)=(10 + 2x)\) (swapping 2x and 10).
• Associative Property of Addition: Used in \((10 + 2x)+7x = 10+(2x + 7x)\) (reassociating addition).
• Commutative Property of Multiplication: Not used, as there's no multiplication swapping (e.g., \(a\cdot b=b\cdot a\) not applied here).

Step2: Identify unused property

From the analysis, the commutative property of multiplication is not used.

Answer:

C. commutative property of multiplication