Bunuel
If \(xy ≠ 0\), is \(x < y\) ?
(1) \(x^4 < y^4\)
(2) \(x^{-3} < y^{-3}\)
In other words,
"Is x smaller than y?", but remember that you can also rewrite the question to
Is \(y-x>0\)? which is equivalent to
"Is y to the right of x on the number line?".
\(xy\neq{0}\) gives us that neither of the variables are zero.
Statement 1:Any non-zero number with an even exponent is positive.
If you take the 4th root of both sides of the inequality \(x^{4}<y^{4}\), you get \(|x|<|y|\).
\(x\) could be \(-2\) and \(y\) could be \(3\), giving us a YES to the question.
\(x\) could be \(3\) and \(y\) could be \(-10\), giving us a NO to the question.
INSUFFICIENTStatement 2:We can rewrite the inequality as \(\frac{1}{x^{3}}<\frac{1}{y^{3}}\).
The signs (positive or negative) are the same for \(x\) and \(y\) as \(x^{3}\) and \(y^{3}\), respectively.
But since the variables are in the denominator, we do not have enough information to answer the question.
\(x\) could be negative and \(y\) could be positive, giving us a YES to the question.
\(x\) could be \(-2\) and \(y\) could be \(-5\), giving us a NO to the question.
INSUFFICIENTStatement 1 and 2 together:Still not enough information.
\(x\) could be \(-2\) and \(y\) could be \(3\), giving us a YES to the question.
\(x\) could be \(-2\) and \(y\) could be \(-5\), giving us a NO to the question.
INSUFFICIENT