keeping in mind that in a parallelogram the diagonals bisect each other, namely cut each other in halves, well, we know by the tickmarks that GJ = JI, but we don't know that if FJ = HJ, that could happen if 7x = x + 6, and that occurs when
[tex]7x = x+6\implies 6x=6\implies x = \cfrac{6}{6}\implies \boxed{x=1}[/tex]
