Question 89030
x = Rolex's age now; y = Rose's age now
:
Just write what it says
"Seven years ago, Rolex was 6 times as old as Rose."
(x-7) = 6(y-7)
Simplify:
x - 7 = 6y - 42
x = 6y - 42 + 7
x = 6y - 35; 
:
"One year from now he will only be twice as old."
(x+1) = 2(y+1)
Simplify:
x + 1 = 2y + 2
x = 2y + 2 - 1
x = 2y + 1
:
Take the 1st equation (x = 6y - 35) and substitute (2y+1) for x
2y + 1 = 6y - 35
1 + 35 = 6y - 2y
4y = 36
y = 36/4
y = 9 yrs is Rose's age now
:
Find x, (Rolex's age)
x = 2y + 1
x = 18 + 1
x = 19 yrs now
:
:
Check solution using,"Seven years ago, Rolex was 6 times as old as Rose."
(19-7) = 6(9-7)
 12 = 6(2); confirms our solution
:
Did this help you understand these kind of problems? This same method will
work for most of these.