Astore sells packages of comic books with a poster.

1 poster + 6 comics = $12.75
or
1 poster + 13 comics = $19.75

a. write a linear function in the form y=mx+b that represents the cost, y, of a package containing any number of comic books.

b. construct arguments. suppose another store sells a similar package, modeled by a linear function with initial value $7.99 which store has the better deal? explain.

a) where is the number of comic books

b) Case B has better deal  

Step-by-step explanation:

a)

Thus, this is in the form of :

Given :

subtracting both ,

The cost of one comic book is $1;

substituting in the first equation ,

The equation is :

b)

Since the shop sells poster with a comic book , initial value is the cost of one comic book plus one poster.

--since its similar.

In case of a. , The cost of one book plus poster = $1+6.75=$7.75

which is lesser than $7.99 .

Thus case B has the best deal.  

25(a-2)(a+2)

Step-by-step explanation:

25a^2 -100  

We can factor out 25

25(a^2 -4)

a^2 -4  is the difference of squares a^2-b^2= (a-b)(a+b)

where a =a and b=2

a^2 -4 = (a-2)(a+2)

25a^2 -100 = 25(a-2)(a+2)