Math Problem Statement

Let a, b, and c be integers. Consider the following conditional statement: If a divides bc, then a divides b or a divides c. Determine whether the statement is true or false. Prove it if it is true or provide a counterexample if it is false

Solution

The given statement is:

If aa divides bcbc, then aa divides bb or aa divides cc.

To determine whether the statement is true or false, let's analyze it by considering a counterexample.

Analysis

The statement asserts that if abca \mid bc, meaning that aa divides the product bcbc, then either aba \mid b or aca \mid c must be true. We need to check if this condition holds in all cases.

Counterexample:

Consider the integers a=6a = 6, b=4b = 4, and c=9c = 9.

  • First, check if abca \mid bc. We calculate: bc=4×9=36.bc = 4 \times 9 = 36. Since 6366 \mid 36 (because 36÷6=636 \div 6 = 6), the condition abca \mid bc is satisfied.

  • Now, check if aba \mid b or aca \mid c:

    • For aba \mid b, we check if 646 \mid 4. This is false, because 4÷64 \div 6 is not an integer.
    • For aca \mid c, we check if 696 \mid 9. This is also false, because 9÷69 \div 6 is not an integer.

Conclusion

In this case, we have abca \mid bc (because 6366 \mid 36), but neither aba \mid b nor aca \mid c. This provides a counterexample showing that the statement is false.

Thus, the conditional statement "If aa divides bcbc, then aa divides bb or aa divides cc" is false.

Further Exploration

If you'd like, we can explore:

  1. Why the distributive property of divisibility does not always apply.
  2. Other counterexamples involving different integers.
  3. Related properties of divisibility and how they can be used in proofs.
  4. The logical structure of conditional statements and their negations.
  5. The role of prime factorization in divisibility problems.

Tip: When dealing with divisibility, always test edge cases or small numbers to identify potential counterexamples!

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Math Problem Analysis

Mathematical Concepts

Divisibility
Number Theory

Formulas

Divisibility condition a | bc
Counterexample method

Theorems

Properties of divisibility

Suitable Grade Level

Grades 9-12