Lets represent:
Roy=x
Rose=y
x-7=6(y-7)
x+1=2(y+1)
x=6y-35
Substitute the value to the second equation:
6y-35=2(y+1)
6y-35=2y+2
Subtract both sides by 2y
4y-35-=2
Add both sides by 35
4y=37
Divide both sides by 4
y=37/4 or 9 and 3 months old
x=6y-35
Substitute the value of Rose's age
x=6(37/4)-35
x=111/2-35
x=41/2 or 20 and 5 months old,
