Answer:
<em>75-9d</em>
Step-by-step explanation:
<em>Hello,</em>
<em>The Answer to the question is 75-9d let me explain why,</em>
<em />
<em>you are asking, how much money is leftover. For me to get that I need to know that for every book it cost "d" dollars.</em>
<em>You know you have $75, and you need 9 books, we don't know how much they cost but we don't really need to. </em>
<em>75 - 9d</em>
<em>75 is the total. You need to subtract it by how many books your buying, 9.</em>
The books are d amount of dollars, so we put 9d so that we know that for every 1 book it cost d amount so technically 9 is the amount of books times d, how much 1 book costs
<em>Hope you can understand, I was having some trouble finding a way to explain it so my bad.</em>
<em />
<em>Also, I haven't done that in a while so sorry if I'm wrong</em>
<u><em>-Nova</em></u>
