Answer:
$1.50 per card
Explanation:
Knowns:
$10 to spends, Wants to buy $7 book and two equal priced cards.
10 = 7 + 2x
Subtract 7 from both sides to find out how much money Dave has after he buys his book.
3 = 2x
Divide each side by 2 to find out how much he cana spend on each card
x = 1.50
i hope this helps!
-TheBusinessMan