Question

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

Answer 1

So lets say bryon is b and doug is d
So we know that bd=40 and b=d+3
2 variables requires 2 equations
substitue b for d+3
d+3)(d)=40
d^2+3d=40
d^2+3d-40=0
d-5)(d+8)=0
d=5 or -8
age can't be negative so d=5.
and b is 5+3 or 8

Answer 2

or you can literally just find numbers that multiply to 40 but have a difference of 3. so 8-5 = 3 and 8*5=40