Gabrielle's age is three times mikhail's age. the sum of their ages is 56, what is their age?

X - age of Mikhail's
3x - age of Gabrielle (three times Mikhail's age)

x + 3x = 56
4x = 56 |:4
x = 14   <-- age Mikhail
3 * x = 14 * 3 = 42   <-- age Gabrielle

As is clear from the job three times the 14 to 42 by adding 14 gives 56, which is behind what they have in total.