Answer:
The twins are 21 years old right now.
(x+4) + (x+4) = 50
Explanation:
Let x = the current age of one of the twins.
They are twins, that means they are the same age. So the other twin is also x years old.
In four years, the age will be x+4.
Both of them together will be:
(x+4) + (x+4)
The question says that total (of their ages in 4 years) will be 50.
(x+4) + (x+4) = 50
Combine like terms.
2x + 8 = 50
Subtract 8.
2x = 42
Divide by 2.
x = 21
The twins are currently 21.
To check: in four years they will be 25; then the sum of their ages will be 50. Check! Hope this helps!