If A= [ array ccc 1 & 2 & x 3 & -1 & 2 array ] and B= [ array c y x 1 array ] be such that AB = [ array l 6 8 array ] , then:

Step-by-step solution

Let A = [ array ccc 1 & 2 & x 3 & -1 & 2 array ] and B = [ array l y x 1 array ] aligned & AB = [ array ccc 1 & 2 & x 3 & -1 & 2 array ] [ array l y x 1 array ] & [ array l 6 8 array ]= [ array l y+2 x+x 3 y-x+2 array ] & [ array l 6 8 array ]= [ array l y+3 x 3 y-x+2 array ] & y+3 x=6 and 3 y-x=6 aligned On solving, we get aligned &x= 6 5 and y= 12 5 & y=2 x aligned