Final answer:
The expression representing the number of baseball cards that Amaya has is 4n - 7, where n is the number of baseball cards Declan has.
Step-by-step explanation:
The question involves creating an algebraic expression to represent the number of baseball cards that Amaya has. If Declan has n baseball cards, Sam has 4 times as many, which would be 4n baseball cards. According to the question, Amaya has 7 fewer baseball cards than Sam. Therefore, the number of baseball cards Amaya has would be Sam's quantity minus 7, so the expression we're looking for is 4n - 7.