we know that
The centroid of a triangle is the intersection of the three medians of the triangle. The coordinates of the centroid are also two-thirds of the way from each vertex along that segment
so
in this problem
The point G is the centroid of the triangle ABC
[tex]AG=2GE[/tex] ------> equation A
we have
[tex]AG=16\ GE=2x[/tex]
substitute in the equation A and solve for x
[tex]16=2*(2x)[/tex]
[tex]16=4x[/tex]
[tex]x=4[/tex]
[tex]BG=2GF[/tex] ------> equation B
we have
[tex]BG=8x[/tex]
substitute in the equation B and solve for GF
[tex]8x=2GF[/tex]
[tex]GF=4x[/tex]
substitute the value of x
[tex]GF=4*4=16[/tex]
therefore
the answer is
She used [tex]GF=2BG[/tex], but the correct statement is [tex]BG=2GF[/tex]