Answer:
So, we purchased 9 songs and 4 games for 20.1$.
So, we purchased 10 songs and 6 games for 25.5$.
So, we purchased 10 songs and 10 games for 33.9$.
Explanation:
We have receive a $35 gift certificate from an online retailer that sells digital music and games. Each song costs $1.29 and each game costs $2.10.
First case:
![9\cdot 1.29=11.61\\\\4\cdot 2.10=8.4\\\\8.4+11.61=20.01](https://img.qammunity.org/2021/formulas/mathematics/college/mzn1lbmmo3esmflvawa7gjfrfdy3im2pzf.png)
So, we purchased 9 songs and 4 games for 20.1$. We have 13 items for 20.1$.
Second case:
![10\cdot 1.29=12.9\\\\6\cdot 2.10=12.6\\\\12.9+12.6=25.5](https://img.qammunity.org/2021/formulas/mathematics/college/6mu96ad4sxjhv8t594phle2lac54mlx9zy.png)
So, we purchased 10 songs and 6 games for 25.5$. We have 16 items for 25.5$.
Third case:
![10\cdot 1.29=12.9\\\\10\cdot 2.10=21\\\\12.9+21=33.9](https://img.qammunity.org/2021/formulas/mathematics/college/ev5x4qiznh2anhylu82g6mokh4k6aj2c94.png)
So, we purchased 10 songs and 10 games for 33.9$. We have 20 items for 33.9$.