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If x/y

is rational, must x and y each be rational?
A) Yes; because the quotient of rationals is rational.
B) No; because x and y could have a common irrational factor.
C) No; because the quotient of irrationals is always irrational.
D) Yes; because x and y must be integers, and integers are rational.

User Tonys
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2 Answers

3 votes

Answer: The answer is B.


Explanation:

No; because x and y could have a common irrational factor.

User Ichiban
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1 vote
The answer is B.

Consider the fraction
(6 √(5) )/(√(5)).

Both the numerator and denominator, when by themselves, are irrational.

However, when they are divided, they result in the rational number
(6 √(5) )/(√(5))=\boxed{6}.

When
p,q have the same irrational factor, the irrational factor will be cancelled from the fraction and (possibly) leave a rational number.


User Aaron Cohn
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8.4k points