Question 360851
Hey, 
So for this one, we need to use variables:
(Jack) = 2(Jill)-20
(jack) + (Jill) = 205
Then we substitute: 2(Jill) -20 for (Jack) in the second equation:
2(Jill) - 20 + (Jill) = 205
3(Jill) = 225
(Jill) = 75
So (Jack) = 2(75) - 20 => 150 - 20 = 130 
Jill= 75
Jack= 130
I hope this helps!