MatricesHard

Question

Matrix A = , if xyz = 50 and 8x + 4y + 3z = 30 then A (adj A) is equal to:-

Options

A.
B.
C.
D.

Solution

A.(Adj. A) = |A| I
|A| = xyz - 8x - 3(z - 8) + 2(2 - 2y)
= xyz - (8x + 3z + 4y) + 28
= 50 - 30 + 28 = 48
∴ A.(Adj A) = 48 I =

Create a free account to view solution

View Solution Free
Topic: Matrices·Practice all Matrices questions

More Matrices Questions

If A = then A2 − 5A + 6I =...If a matrix A is such that 3A3 + 2A2 + 5A + I = 0, then A-1 is equal to-...If A = [aij] is scalar matrix of order n x n such that aij = k for all i, then |A| equals -...If A = , then 2A =...If A = , then AA′ equals -...