Answer:
x = 9
Step-by-step explanation:
M is at the midpoint of GA and N is at the midpoint of HA, hence
MN is a mid-line segment and is half the length of GH, that is
5x = [tex]\frac{1}{2}[/tex](15x - 45) ← multiply both sides by 2
10x = 15x - 45 ( subtract 15x from both sides )
- 5x = - 45 ( divide both sides by - 5 )
x = 9
