Question

Lian and her younger sister Ella are 4 years apart. The sum of their ages is 20. Let l be Lian’s age in years and let e be Ella’s age in years.

The system of linear equations that models the scenario is:
l – 4 = e
l + e = 20
How old is each sister?
Lian is years old and Ella is years old.

Answer 1

Lian is 12 years old and Ella is 8 years old!

Answer 2

L = 12
E = 8
12 - 4 = 8
12 + 8 = 20.