Question

The pairs of linear equations which have the unique solution x = 2, y = –3 is/are:

• A. 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

Answer 1

Answer: (A), (D)

The correct options are
A

x + y = –1 ; 2x – 3y = –5

D

x – 4y –14 = 0 ; 5x – y – 13 = 0

Option A:
x + y = –1
2x + 3y = –5

Solving by elimination we get x = 2 and y = -3.

Option D:
x-4y=14
5x-y=13

Using cross multiplication method and solve, we get x = 2 and y = -3.