I need help mate. You have $75 and need to buy 9 books at the bookstore and each book costs d dollars.

​Write an algebraic expression to represent the amount of money left over.

75-9d

Step-by-step explanation:

Hello,

The Answer to the question is 75-9d let me explain why,

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.

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.

75 - 9d

75 is the total. You need to subtract it by how many books your buying, 9.

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

Hope you can understand, I was having some trouble finding a way to explain it so my bad.

Also, I haven't done that in a while so sorry if I'm wrong

-Nova

δabc ≅ δdcb by sas because

db ≅ ac . . given (side)

bc ≅ bc . . reflexive property (side)

∠dbc ≅ ∠ acb . . alternate interior angles where transversal bc crosses parallel lines bd and ac (included angle)