If 3x + 2|y| + y = 7 and x + |x| + 3y = 1, then x + 2y is
Explanation:
Case 1: x, y > 0 ⇒ 3x + 3y = 7 and 2x + 3y = 1 Solving these two equations we get, x = 6 and y = -11/3 This is rejected as y should be positive.
Case 2: x > 0, y < 0 ⇒ 3x - y = 7 and 2x + 3y = 1 Solving these two equations we get, x = 2 and y = -1 This is accepted. ∴ x + 2y = 2 + 2 × -1 = 0
Case 3: x < 0, y > 0 ⇒ 3x + 3y = 7 and 3y = 1 Solving these two equations we get, x = 2 and y = 1/3 This is rejected as x should be negative.
Case 4: x, y < 0 ⇒ 3x - 3y = 7 and 3y = 1 Solving these two equations we get, x = 8/3 and y = 1/3 This is rejected as and y should be negative.
Hence, option (c).
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