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

Present age of Byron = b

Present age of Doug = d

Byron is 3 years older than Doug

b=d+3 ... (1)

The product of their age is 40

bd=40 ... (2)

Substitute the value of b from (1) to (2)

(d+3) d=40

d^2+3d=40

d^2+3d-40=0

Now solve for d

d^2+8d-5d-40=0

d (d+8) - 5 (d+8) = 0

(d-5) (d+8) = 0

d-5=0 or d+8=0

d=5 or d=-8

d=-8 (inadmissible)

So d=5

Put the value of d in (1)

b=d+3 ... (1)

b=5+3

b=8

Present age of Byron = b = 8 years old

Present age of Doug = d = 5 years old