Let x be Pamela's age, and y Jiri's age.
"Pamela's age is 2 times Jiri's age" can be represented by x = 2y
"The sum of their ages is 63" So x + y = 63
We can now create a system of 2 equations:
x = 2y (1)
x + y = 63 (2)
Let's take the algebraic value of x from equation (1) and replace it in equation (2):
x + y = 2y + y = 3y
So 3y = 63
Divide both sides by 3 to isolate y on a side and its value on the other:
(3y)/3 = 63/3
y = 21
So Jiri's age is 21 years old.
Hope this Helps! :)
