To analyze the problem, we can define the sets based on the subjects studied by the students in the class. Let's denote:
- \( F \) for the set of students studying French
- \( M \) for the set of students studying Mathematics
- \( H \) for the set of students studying History
We can denote:
- \( |F| \) = number of students studying French
- \( |M| \) = number of students studying Mathematics
- \( |H| \) = number of students studying History
From the information provided, we can summarize the students studying only one subject and those studying combinations of subjects as follows:
- Students studying only French: \( |F| - (FM + FH + FMH) = 9 \)
- Students studying only Mathematics: \( |M| - (FM + HM + FMH) = 8 \)
- Students studying only History: \( |H| - (FH + HM + FMH) = 1 \)
- Students studying both French and Mathematics but not History: \( |FM| = 7 \)
- Students studying both French and History but not Mathematics: \( |FH| = 9 \)
- Students studying both History and Mathematics but not French: \( |HM| = 8 \)
- Students studying all three subjects: \( |FMH| = x \)
Now, we also know that the total number of students studying at least one subject is: \[ |F \cup M \cup H| = 38 \]
Let's put this information into a Venn diagram representation and create an equation.
Venn Diagram Set Notation
We can denote:
- \( |F \cap M| = 7 + x \) (French and Mathematics, including those studying all three)
- \( |F \cap H| = 9 + x \) (French and History, including those studying all three)
- \( |M \cap H| = 8 + x \) (Mathematics and History, including those studying all three)
Using the principle of inclusion-exclusion for three sets: \[ |F \cup M \cup H| = |F| + |M| + |H| - |F \cap M| - |F \cap H| - |M \cap H| + |F \cap M \cap H| \]
Substituting what we have, we can express the total number of students as: \[ 38 = (9 + (7 + x) + (9 + x) + (8 + x)) - (7 + x) - (9 + x) - (8 + x) + x \]
Setting up the equation
Simplifying the equation: \[ 38 = (9 + 7 + 9 + 8 + 2x) - (7 + 9 + 8 + 2x) + x \] \[ = 33 + 2x - 24 - 2x + x \] \[ = 33 - 24 + x \] \[ = 9 + x \]
Thus, our equation would be: \[ 9 + x = 38 \]
Taking \( x \) to one side gives: \[ x = 38 - 9 \] \[ x = 29 \]
Final Answer
- The value of \( x \) is 29, meaning 29 students are studying all three subjects.
- The equation that illustrates the relationship in terms of \( x \) is: \[ 38 = 9 + 7 + 8 + 1 + 9 + 8 + x \]
Note
Please double-check calculations if you re-evaluate combinations to ensure we classify students in various subject categories correctly. It’s also important to visualize through a Venn diagram for clarity on student representation in each intersection.