Answer:
The age of triplets is 42 years old
Explanation:
The question in English is
The sum of the ages of twins and triplets is 150 years if the ages are exchanged the new sum is 120 years. What is the age of triplets?
Let
x -----> twins age
y ----> triplets age
we know that
2x+3y=150 ------> equation A
2y+3x=120 -----> equation B
Solve the system by graphing
The intersection point both graphs is the solution of the system
The solution is the point (12,42)
see the attached figure
therefore
The age of triplets is 42 years old