VITEEE 2011 Paper

Given system of equations are
2x + y - 5 = 0 ... (i)
x - 2y + 1 = 0 ... (ii)
and 2x - 14y - a = 0 ... (ii)
This system is consistent
∴ |

2	1	−5
1	−2	1
2	−14	−a

| = 0
⇒ 2 (2a + 14) - 1 (- a - 2) - 5 (- 14 + 4) = 0
⇒ 4a + 28 + a + 2 + 50 = 0
⇒ 5a = - 80 ⇒ a = - 16