(Q.18). For what value of ‘p’ the following pair of equations has a unique solution.

2x + py = – 5 and 3x + 3y = – 6

Given: 2x + py = – 5

3x + 3y = – 6

To have an unique solution we should have

a1
a2
 ≠
b1
b2
≠
;
⇒ p ≠
×

⇒ p ≠

∴ The pair has solution when p ≠ .