Answer for A)
$23.65=$5.95+$2.95x
This is equation for this one because we know that 23.65 is the total money they have total and 5.95 cost for book and 2.95 dollar what each magazine. BUT we need to know how many magazines so it will show on answer B)
Answer for B)
23.65=5.65+2.95x
23.65-5.95=-5.95+2.95x
17.70=2.95x
17.70/2.95=2.95/2.95
6=x
So the answer is 6 magazine! We can buy only up to 6 magazines because it enough money to pay everything with book and magazine