Official Solution:If \(x + y ≠ 0\), is \(\frac{1}{x + y} < 1\)? (1) \(x^2 = y^2\)
\(x^2 - y^2 = 0\);
\((x - y)(x + y) = 0\).
Given that \(x + y ≠ 0\), we deduce that \(x - y = 0\), which is equivalent to \(x = y\).
The
question now becomes:
Is \(\frac{1}{x + y} < 1\)?
Is \(\frac{1}{2x} < 1?\)
Is \(\frac{1}{x} < 2\)?
We do not have enough information to answer this question. Hence, statement (1) is insufficient.
(2) \(\frac{1}{x} < 2\).
This statement provides no information about \(y\), so we cannot determine whether \(\frac{1}{x + y} < 1\). Insufficient.
(1)+(2) From (1), the question was simplified to "Is \(\frac{1}{x} < 2\)?" and (2) directly provides a YES answer to that. Sufficient
Answer: C