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Question
Check whether the following matrices are invertible or not:
`[(1, 2, 3),(2, 4, 5),(2, 4, 6)]`
Solution
Let A = `[(1, 2, 3),(2, 4, 5),(2, 4, 6)]`
Then, |A| = `|(1, 2, 3),(2, 4, 5),(2, 4, 6)|`
= 1(24 – 20) – 2(12 – 10) + 3(8 – 8)
= 4 – 4 + 0
= 0
∴ A is a singular matrix.
∴ A is not invertible.
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