Final answer:
The property used to justify each step of simplification in the given expression is the distributive property, the commutative property, and the associative property.
Step-by-step explanation:
Step a: Distributive property. Multiply 4 by each term inside the parentheses. This gives us 4x + 4.
Step b: Commutative property. Rearrange the terms so that the constant term, which is 3 in this case, comes after the expression 4x + 4. This gives us 4x + 4 + 3.
Step c: Associative property. Group the constants, which are 4 and 3, and add them together. This gives us 4x + (4 + 3).
Step d: Simplify the expression.
Add 4 and 3 together, which gives us 7. The final expression is 4x + 7.