Let's analyze the given equation: \((x - 1)(y + 3)(xy + 3) = 0\)
For the product of these three factors to be zero, at least one of the factors must be zero. This gives us three possible scenarios (keeping in mind \(x\) and \(y\) must be integers):
- \(x - 1 = 0 \implies x = 1\) (and \(y\) can be any integer)
- \(y + 3 = 0 \implies y = -3\) (and \(x\) can be any integer)
- \(xy + 3 = 0 \implies xy = -3\). The possible integer pairs for \((x, y)\) are \((1, -3)\), \((-1, 3)\), \((3, -1)\), and \((-3, 1)\).
Now, let's evaluate each statement to see which
must be true:
I. If x = -1, |y| is a prime numberIf \(x = -1\), then Scenario 1 (\(x = 1\)) is impossible. Therefore, we must satisfy either Scenario 2 or Scenario 3:
If Scenario 2: \(y = -3 \implies |y| = |-3| = 3\)
If Scenario 3: \(xy = -3 \implies (-1)y = -3 \implies y = 3 \implies |y| = |3| = 3\)
In both valid scenarios, \(|y| = 3\). Since 3 is a prime number, this statement MUST be true.
Statement I is TRUE.II. If |y| is not a prime number, x is not a prime numberTo prove this false, we just need to find one counterexample where \(|y|\) is
not prime, but \(x\)
is prime.
Looking at the pairs from Scenario 3 above, we have the pair \((3, -1)\).
Here, \(y = -1 \implies |y| = 1\) (1 is
not a prime number).
However, \(x = 3\) (which
is a prime number).
Since we found a case that directly contradicts the statement, it does not have to be true.
Statement II is FALSE.III. If x is a prime number, y/x is not an integerTo prove this false, we just need a counterexample where \(x\) is prime and \(y/x\)
is an integer.
From Scenario 2, we know \(y = -3\) is a valid solution for
any integer \(x\).
Let's choose \(x = 3\) (a prime number).
If \(x = 3\) and \(y = -3\), then \(y/x = -3/3 = -1\).
Since -1
is an integer, this statement does not have to be true.
Statement III is FALSE.Since only Statement I must be true, the correct option is A.