Answer:
Sam is 24 years old and his mother is 48 years old.
Step-by-step explanation:
Equations
Let's call
x = Sam's current age
Since Sam's mother is twice as old as Sam:
2x = Sam's mother current age
x + 12 = Sam's age in 12 years
2x - 12 = Sam's mother age 12 years ago
These two last expressions are equal:
x + 12 = 2x - 12
Subtracting x and adding 12:
x = 24
2x = 48
Sam is 24 years old and his mother is 48 years old.
