Answer: Aiden bought 8 notebooks and 5 covers.
This is a system of equations problem. To solve this, we have to write 2 different equations and then solve them.
Our equations are:
x + y = 13
1.37x + 1.08y = 16.36
Where x is the number of notebooks and y is the number of covers.
To solve these equations, you can use anyone of these methods:
1) Graphing
2) Substitution
3) Elimination
The easiest way would be to graph them with a graphing calculator and find the point of intersection.