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Question
Find k if the following matrix is singular:
`[(7, 3),(-2, "k")]`
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Solution
Let A = `[(7, 3),(-2, "k")]`
Since A is a singular matrix,
IAI = 0
∴ `|(7, 3),(-2, "k")|` = 0
∴ 7k – (– 6) = 0
∴ 7k + 6 = 0
∴ 7k = – 6
∴ k = `(-6)/7`.
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