Solve for x and y in the equations below
x2 – y2 = 4
x + y = 2
x2 – y2 = 4
x + y = 2
-
A.
x = 0, y = -2 -
B.
x = 0, y = 2 -
C.
x = 2, y = 0 -
D.
x = -2, y = 0
Correct Answer: Option C
Explanation
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
—–
2x = 4
—–
x = 2, when y = 0
There is an explanation video available below.