Answer: X= John's age , Y= Fernando's age, Z = Age of Luis uncle
Step-by-step explanation:
Given: John is 20 years younger than fernando.
i.e. John' age + 20 = Fernando's age
So in the given equation "X+20=Y " , X= John's age and Y= Fernando's age.
From this , John's age: X= Y-20 (i)
Also, Luis uncle is 3 years younger than his dad( John).
Age of Luis uncle = John's age -3
=X-3
= Y-20-3 [From i]
So in the given equation Y-20-3=Z , Z = Age of Luis uncle
I would need more information and a picture of the problem to help you.
It is a straight line of symmetry because if you have a paper A and you fold it, it will form a straight line, and that is also meaning a straight line of symmetry. If you fold it any other way, it will not be a line of symmetry.
Hope this helps you ;)
I think one could be (2, 11).