x = 0, y = -2
x = 0, y = 2
x = 2, y = 0
x = -2, y = 0
Correct answer is C
x2 - y2 = 4 .... (1)
x + y = 2 .... (2)
Simplify eqn (1)
(x + y)(x - y) = 4
From eqn (2)
x + y = 2 so substitute it into simplified eqn (1), we have
2 (x - y) = 4
therefore,
x - y = 2 ... (1)
x + y = 2
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2x = 4
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x = 2, when y = 0