sure you understand what it says.
Solve:
STRATEGY: Think of possible values and substitute.
"Guess and check."
SAT TIP: In a fractional exponent,
the numerator is the power; the denominator is the root.
the base and its exponent are the denominator of a fraction.
Now, if you have, ------------------------------ = -----------------------------
1 the square root of (x - y)
(x + y) 1
And, if you square both sides, you have, ------------ = -----------
1 (x - y)
Now, cross multiply: (x + y) (x - y) = 1
(x + y) (x - y) are the factors of the difference ot two perfect squares !
STRATEGY: Read the question again to be sure
you know what it asks.
The answer is E.
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