if ef=2x-6 fg=3x-9 and eg=25 what is the value of x ef and fg

I assume f is a point on the line eg, between e and g.

Just remember that ef+fg = eg

2x-6 + 3x-9 = 25
5x - 15 = 25
5x = 40
x = 8

so,

ef = 10
fg = 15