Answer: Commutative Property (choice C)
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Explanation:
Here are all of the justifications for each step
- Step 1. None needed. This is the original expression
- Step 2. Distributive property
- Step 3. Multiply (the 3 and 5 multiply to 15)
- Step 4. Commutative property. Specifically, this is the commutative property of addition which allows us to add any two numbers in any order we want. In this case, the -15 and 4x terms swap places.
- Step 5. Associative property. The parenthesis group the first two terms away from the third term.
- Step 6. Combine like terms. Both 3x and 4x have an x only so they are like terms that combine to 7x. You can think of it as 3+4 = 7, then you just tack an x onto everything to get 3x+4x = 7x.
