1957 AMC 12 Question 45
AMC12 · 1957 AMC 12
If two real numbers $x$ and $y$ satisfy the equation $\dfrac xy=x-y,$ then:
$x\ge4$ or $x\le0,$ where $x\ge a$ means
that $x$ can take any value greater than $a$ or equal to
$a$
$y$ can equal $1$
both $x$ and $y$ must be irrational
$x$ and $y$ cannot both be integers
both $x$ and $y$ must be rational