Answer:
Total amount spent = $10,000
Cost of one HD headphones = $70
So, cost of 110 HD headphones = [tex]70\times110=7700[/tex] dollars
Hence, amount left to purchase basic headphones = [tex]10000-7700=2300[/tex] dollars
So, the store can buy x headphones from $2300. Where x can be found by dividing 2300 by the cost of 1 headphones.