Gwenn one fourth as old as her mother.


Clear the fraction by multiplying both sides by 4


Six years ago, she was one tenth as old as her mother.
Six years ago she was G-6 and her mother was M-6
...she was one tenth as old as her mother.


Clear the fraction by multiplying both sides by 10










So you have this system of equations:
Solve that by substitution and you get that
Gwenn is 9, and her mother is 36.
Edwin