Çözüldü Age Problem

If the sum of ages of Fatma and Gül (today) is 41, and when Fatma was Gül's (present) age, Gül was 4 years old, how old is Fatma now?
https://i.ibb.co/72XS9j3/sum-of-ages.png
https://scontent-vie1-1.xx.fbcdn.ne...=59f6e46a3ead3ac2f385f22ee935ff57&oe=5C9B8501
https://www.facebook.com/photo.php?...&set=gm.2495956360419714&type=3&theater&ifg=1

F + G = 41....(I)
x years before Gül was born F - x = G....(II) and for Gül, G - x = 4....(III)
Subtracting the equation (III) from (II); F - x - G + x = G - 4 and simplifying, F - 2G = -4....(IV)
Solving (left for the interested students) the equations (I) and (IV), F = 26

Timeline:

https://i.ibb.co/QbtRnbf/Fatma-G-l.png

Note: The words in parentheses are suggested not to be given in exams so that students should discern on their own.