If X= [ array l x y z array ] is a solution of the system of equations A X=B , where adj A= [ array ccc 4 & 2 & 2 -5 & 0 & 5 1 & -2 & 3 array ] and B = [ array l 4 0 2 array ] , then |x+y+z| is equal to :

Step-by-step solution

X = 1 |A| adj (A) B . | adj (A)| = 4(10)-2(-20)+2(10) = 100 , so |A|^2=100 |A|= 10 . adj (A) B = pmatrix 16+0+4 -20+0+10 4+0+6 pmatrix = pmatrix 20 -10 10 pmatrix x+y+z = 20-10+10 |A| = 20 10 = 2 |x+y+z|=2