If for AX = B,B = [9 52 0] and A-1 = [3& -1/2&-1/2 -4&3/4&5/4 2&-3/4&-3/4] then X is equal to :

Question

If for AX = B,B = [9 52 0] and A-1 = [3& -1/2&-1/2 -4&3/4&5/4 2&-3/4&-3/4] then X is equal to : (A) [3 3/4 -3/4] (B) [-1/2 1/2 2] (C) [-4 2 3 ] (D) [1 3 -21 ]

Tardigrade Admin · Accepted Answer

Here X = A-1 B i.e., X = [3&-1/2&-1/2 -4&3/4&5/4 2&-3/4&-3/4]3×3 [9 52 0]3×1 = [1 3 -21]3×1

Q. If for $A X = B, B = ⎣ ⎡ 9520 ⎦ ⎤$ and $A^{- 1} = ⎣ ⎡ 3 - 4 2 - 1/2 3/4 - 3/4 - 1/2 5/4 - 3/4 ⎦ ⎤$ then X is equal to :

$⎣ ⎡ 3 3/4 - 3/4 ⎦ ⎤$

$⎣ ⎡ - 1/2 1/2 2 ⎦ ⎤$

$⎣ ⎡ - 4 23 ⎦ ⎤$

$⎣ ⎡ 13 - 21 ⎦ ⎤$

Here $X = A^{- 1} B$
i.e., X = $⎣ ⎡ 3 - 4 2 - 1/2 3/4 - 3/4 - 1/2 5/4 - 3/4 ⎦ ⎤_{3 \times 3} ⎣ ⎡ 9520 ⎦ ⎤_{3 \times 1}$
$= ⎣ ⎡ 13 - 21 ⎦ ⎤_{3 \times 1}$

Q. If for AX=B,B=⎣⎡​9520​⎦⎤​ and A−1=⎣⎡​3−42​−1/23/4−3/4​−1/25/4−3/4​⎦⎤​ then X is equal to :

⎣⎡​33/4−3/4​⎦⎤​

⎣⎡​−1/21/22​⎦⎤​

⎣⎡​−423​⎦⎤​

⎣⎡​13−21​⎦⎤​