Answer:
$18.26
Explanation:
The total price is $42.20
We want to know how much 1 of those books cost
We know that $5.67 were for her dog
So we are gonna subtract that from $42.20
$42.20-$5.67=36.53
Now your gonna divide that by 2 because she got 2 books
So 36.53/2=$18.26
1 book=$18.26