Question

byron is 3 years older than doug. the product of their ages is 40. how old is doug?

Answer 1

Doug's age is some unknown x.
Byron is 3 years older than that so he'd be x+3;
multiply these 2 and set them equal to 40. Solve.

Answer 2

Dougs age = x
Byron = (x + 3) yrs
Multiply the two ages to get 40: x * (x + 3) = 40
x^2 + 3x - 40 = 0
(x+8)(x-5) = 0
Factor: x = -8 or x = 5
The age cannot be negative so he is 5 yrs old