Question 332194
let rendell's age be x
father's age = 9x.
..
1 year ago their ages were 
x-1
9x-1
..
9x-1=11(x-1)+2
9x-1=11x-11+2
9x-11x=-11+1+2
-2x=-8
x=4 Rendell's age now
father's age = 9*4=36 years