You can put this solution on YOUR website! Let S = Sonya's current age. Then Isaac's age is S+6.
In 3 years, Sonya will be S+3 and Isaac will be S+9, and the sum of their ages will be 74:
S+3 + S+9 = 74 -> 2S = 62 -> S = 31
So Sonya is 31 and Isaac is 37