GH = 13(x-1) = 13x - 13
Suppose I is between point G and H, then
GH = GI + IH
13x - 13 = 16 + 4x + 25
Let's solve for x
First, collect like term.
13x - 4x = 16 + 25 + 13
9x =54
Divide both-side of the equation by 9
x = 54/9
x= 6
We can now find GH by simply substituting x = 6 into GH = 13x -13
GH = 13(6) - 13
=78 - 13
=65
Therefore, the length of GH = 65