Question 754431
A father is four times older than his son. If you subtract 60 from the square of the son's age you get the fathers age. How old are they? 

let son's age be x, then father's age is 4x, also

4x = x^2 - 60   and

x^2 -4x -60 = 0

factor the polynomial

(x+6)*(x-10)=0

solutions for x are -6 and 10

we choose the value 10 for x since a person can not be negative years old  :-)

so the son is 10 years old and the father is 4*10 or 40 years old