Question

2 3
12. If A = 3 -2 1 then show that A3 - 23A - 401 = 0
4 2
1 solve this with steps
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Answer 1

if A = 3 - 2 = 1

therefore A = 1

A3 - 23A - 401 = 421

using the value A = 1

(1) 3 - 23(1) - 401 = 0

3 - 23 = 0 + 401

-20 = 401

0 = 401 + 20

0 = 421