∣T∣=∣∣x2y2z2w22x+12y+12z+12w+14x+44y+44z+44w+46x+96y+96z+96w+9∣∣
if we add 2nd and 3rd columns, and subtract it from 4th column, we get:
∣T∣=∣∣x2y2z2w22x+12y+12z+12w+14x+44y+44z+44w+44444∣∣
if we multiply 2nd column by 2, and subtract it from 3rd column, we get:
∣T∣=∣∣x2y2z2w22x+12y+12z+12w+122224444∣∣
then, multiplying 3rd column by 2, we get:
2∣T∣=∣∣x2y2z2w22x+12y+12z+12w+144444444∣∣=0
since two columns of a determinant are identical.
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