Tony and his sister Maria have the same birthday, but Tony is four years YOUNGER than Maria. Let the variable x represent Tony’s age and y represent Maria’s age. Which graph represents the relationship between Tony’s age and Maria’s age? (Circle your answer)
The correct graph representing the relationship between Tony's age and Maria's age would be:
x-axis: Maria's age (y)
y-axis: Tony's age (x)
The graph should show a straight line with a positive slope, indicating that as Maria's age increases, Tony's age also increases.
To determine the relationship between Tony's age (x) and Maria's age (y), we need to consider the given information: Tony is four years younger than Maria.
This means that Tony's age, x, can be represented as y - 4, where y represents Maria's age.
Let's analyze the answer choices and find the graph that represents this relationship:
1. A graph showing a straight line with a positive slope: This graph does not represent the relationship because it suggests that Tony's age increases at a constant rate. However, the problem states that Tony is four years younger than Maria, which means the gap between their ages is constant (4 years).
2. A graph showing a straight line with a negative slope: This graph does not represent the relationship either because it suggests that Tony's age decreases as Maria's age increases, which is not true. Tony is younger, but his age will still increase as time passes.
3. A graph showing a curved line: This graph does not represent the relationship either. A curved line suggests a non-linear relationship, which does not apply to the situation. The age gap between Tony and Maria is constant.
4. A graph showing a straight line with a negative slope, starting from a point (4,0): This graph correctly represents the relationship between Tony and Maria's age. It shows that Tony's age (x) is always 4 years less than Maria's age (y). This aligns with the information given in the problem statement.
Therefore, the correct graph that represents the relationship between Tony's age and Maria's age is the one in option 4.