Question 584727
Let f = Faye's age
Her grandfather's age is 7 more than 6 times Faye's age
In equation form, her grandfather's age can be written as 6f + 7
The square of Faye's age is 9 more than her grandfather's:
f^2 = (6f+7) + 9
f^2 - 6f - 16 = 0
Factor:
(f-8)(f+2) = 0
Since Faye's age has to be positive, the answer is f=8
So Faye is 8 yrs old, her grandfather is 6*8 + 7 = 55 yrs old