Answer: Andy has 41 books
Erica has 82 books
Clay has 56 books
Step-by-step explanation:
Let x represent the number of books that Andy has.
Let y represent the number of books that Erica has.
Let z represent the number of books that Clay has.
Andy, Erica, and Clay have a collection of books totaling 179 books. This means that
x + y + z = 179 - - - - - - - - -1
Erica has twice as many books as Andy. It means that
y = 2x
Andy has 15 fewer books than Clay. It means that
x = z - 15
z = x + 15
Substituting y = 2x and z = x + 15 into equation 1, it becomes
x + 2y + x + 15 = 179
4x = 179 - 15 = 164
x = 164/4 = 41
y = 2x = 2×41 = 82
z = x + 15 = 41 + 15 = 56
