Question 51889
Let Precys present age be x yrs 
A year ago  her age was (x-1) yrs
So Alex age was 7(x-1) yrs
Alex present age is 7(x-1)+1
In 3 yrs Precys age will be x+3
In 3 yrs Alex age will be 3(x+3)
3(x+3)=7(x-1)+1+3
3x+9=7x-7+4
3x-7x=-11-9
-4x=-20
x=5
So Precys present age is 5 yrs and Alex present age is 7(5-1)+1=28+1=29 yrs