Answer:
David gets £34, Egil gets £119 and Frances gets £153. 
Explanation:
Let the amount of money David gets be 2x, Egil be 7x and Frances be 9x. 
7x = 2x + 85 
7x - 2x = 85
5x = 85
x = 85 ÷ 5
x = 17 
David (2x) = 2 × £17
 = £34
Egil (7x) = 7 × £17
 = £119
Frances (9x) = 9 × £17
 = £153