Gfsseyujbbiittc dfiiyresc jimmbvcduyh.
Answer:

Step-by-step explanation:
Remember that

Let
x ----> the total cost of the books
we know that
The total cost of the book multiplied by 0.65 must be equal to $438.75
so
The linear equation that represent this situation is

solve for x

-2 - 3 = -5
The answer is negative 5.
the idea of showing that multiplying by 1 is true because as long as A and B follow the same ratio pattern (ie. 1n:2n is the same as 2n:4n) the statement will always be true
According to Google, yes.... any details, I have no idea, but I hope I helped in any way, haha
Good luck~~