If A= pmatrix1&3&-2\-3&0&-5\2&5&0 pmatrix and A( adjA)=KI, then the value of K is (where I is unit matrix of order 3)

Question

Accepted Answer

Correct answer: D. (d) : A=(13-2-30-5250) and A ( adj ⁡A )= KI We know that, A ( adj ⁡A )= |A | I ⇒K= |A | Now, |A |=1 (0+25 )-3 (0+10 )-2 (-15 ) (Expanding along R_1 ) =25-30+30=25 ∴K=25

$If A = 1 - 3 2 305 - 2 - 5 0 and A (adj A) = K I, then the value of K is (where I is unit matrix of order 3)$

Solution

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