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Question
If A = `[(2,3),(1,2)]`, B = `[(1,0),(3,1)]`, then B-1A-1 = ?
Options
`[(-2,-3),(-7,11)]`
`[(2,-3),(-7,11)]`
`[(2,3),(7,11)]`
`[(-2,-3),(-7,-11)]`
MCQ
Solution
`[(2,-3),(-7,11)]`
Explanation:
We have,
A = `[(2,3),(1,2)]`, and
B = `[(1,0),(3,1)]`
AB = `[(2,3),(1,2)] [(1,0),(3,1)]`
AB = `[(11,3),(7,2)]`
|AB| = 22 - 21 = 1
∴ `("AB")^-1 = [(2,-3),(-7,11)]`
∴ We know that,
B-1 A-1 = (AB)-1
∴ B-1 A-1 = `[(2,-3),(-7,11)]`
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