If 
, then A-1 exists if
Given 
⇒ |A| = 2 (6 – 5) - λ (0 – 5) + (-3) (0 – 2)
= 2 + 5λ + 6
= 5λ + 8
We know that A-1 exists if A is non – singular matrix i.e. |A| ≠ 0.
∴ 5λ + 8 ≠ 0
⇒ 5λ ≠ -8
So, A-1 exists if and only if 
.
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If , then A-1 exists if
Given
⇒ |A| = 2 (6 – 5) - λ (0 – 5) + (-3) (0 – 2)
= 2 + 5λ + 6
= 5λ + 8
We know that A-1 exists if A is non – singular matrix i.e. |A| ≠ 0.
∴ 5λ + 8 ≠ 0
⇒ 5λ ≠ -8
So, A-1 exists if and only if .