1. **State the problem:** Valeria spent a total of 21 on 8 games and rides. Each game costs 1.50 and each ride costs 3. We want to find the number of games $x$ and rides $y$.
2. **Set up the system of equations:**
- Total number of games and rides: $$x + y = 8$$
- Total cost: $$1.5x + 3y = 21$$
3. **Express one variable in terms of the other:** From the first equation, $$y = 8 - x$$.
4. **Substitute into the cost equation:**
$$1.5x + 3(8 - x) = 21$$
5. **Simplify and solve for $x$:**
$$1.5x + 24 - 3x = 21$$
$$-1.5x + 24 = 21$$
$$-1.5x = 21 - 24$$
$$-1.5x = -3$$
$$x = \frac{-3}{-1.5} = 2$$
6. **Find $y$ using $y = 8 - x$:**
$$y = 8 - 2 = 6$$
7. **Interpretation:** Valeria played 2 games and went on 6 rides.
8. **Graphical representation:** The system can be graphed with lines:
$$y = 8 - x$$
and
$$y = \frac{21 - 1.5x}{3} = 7 - 0.5x$$
The intersection point $(2,6)$ is the solution.
**Final answer:** Valeria played **2 games** and went on **6 rides**.
Games Rides B5C175
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