Question 12 - MCQs from NCERT Exemplar - Chapter 3 Class 10 Pair of Linear Equations in Two Variables

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Question 12 A pair of linear equations which has a unique solution x = 2, y = –3 is: x + y = –1, 2x – 3y = –5 (b) 2x + 5y = –11, 4x + 10y = –22 (c) 2x – y = 1, 3x + 2y = 0 (d) x − 4y − 14 = 0, 5x − y − 13 = 0 Since solving equations will take a lot of time We check which equations satisfy x = 2, y = −3 Option A x + y = –1 and 2x – 3y = –5 Here, x = 2, y = −3 is satisfied by 1st equation, but not the 2nd equation Hence, option (A) is incorrect Option B 2x + 5y = –11 and 4x + 10y = –22 Here, x = 2, y = −3 is satisfied by 1st equation, and the 2nd equation Hence, option (B) is correct Option C 2x – y = 1 and 3x + 2y = 0 Here, x = 2, y = −3 is not satisfied by 1st equation Hence, option (C) is incorrect Option D x − 4y − 14 = 0 and 5x − y − 13 = 0 Here, x = 2, y = −3 is satisfied by 1st equation, and the 2nd equation Hence, option (D) is also correct