Devaughn's age is two times Sydney's age. The sum of their ages is

66. What is Sydney's age?

if you look at the question itself, we know the sum of their ages is 66 and that Devaughn is twice the age of Sydney.

D = 2s

66-2s=s

3s=66

s=22

Sydney is 22, Devaughn is 44, equal to sum of 66

D = devaugn's age

s = sidney's age

so, we know Devaugh's age is twice as Sydneys, so d = 2*s or 2s

and we know their sum is 66

or d + s = 66

since d = 2s, thus

(2s) + s = 66 < - - - solve for "s" to see Sidney's age

what about Devaugn's? well d = 2s