Question

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

i. x + y = –1 ; 2x + 3y = –5
ii. 2x + 5y = –11 ; 4x + 8y = –22
iii. 2x – y = 1 ; 3x + 2y = 0
iv. x – 4y –14 = 0 ; 5x – y – 13 = 0

• A. i and ii
• B. ii and iii
• C. iii and iv
• D. i and iv

Answer 1

The correct option is D i and iv

Option (i)
x + y = –1
2x + 3y = –5
Solving by elimination we get x = 2 and y = -3.

Option (iv)
x - 4y = 14
5x - y = 13
Using substitution method (any method can be used) and solving, we get
x = 2 and y = -3

So, option D is correct.