BITSAT 2012 Paper

Consider first two equations :
2x + 3y = –4 and 3x + 4y = –6
We have Δ = |

2	3
3	4

| = - 1 ≠ 0
Δx = |

−4	3
−6	4

| = 2 and Δy = |

2	−4
3	−6

| = 0
∴ x = –2 and y = 0
Now this solution satisfies the third, so the equations are consistent with unique solution.