The midpoint is exactly in the middle
meaning
VW = WX
3x+7 = x + 25
solve from x
3x + 7 = x + 25
subtract 7 from both sides
3x = x + 18
subtract x from both sides
2x = 18
divide both sides by 2
x = 9
Now we have x = 9 but we aren't done.
plug what we found into the expressions
3x + 7
3(9) + 7
27 + 7
34
x + 25
9 + 25
34
34 + 34
68
The length of VX is 68.
Or option D.) 68
Hope this helps