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?

Answer 1

Answer:

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

Step-by-step explanation:

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.

Let E be Ella’s age in years.

The system of linear equations that models the scenario is:

$L-4=E$ this gives $L=E+4$

$L+E=20$

Putting L=E+4 in the second equation

$E+4+E=20$

$2E=20-4$

$2E=16$

So, $E=8$

Now we have , L+E=20

$L+8=20$

So, $L=12$

Therefore, Lian is 12 years old and Ella is 8 years old.

Answer 2

L - 4 = E
L = E + 4
remplace
E + 4 + E = 20
2e =16
e = 16/2
Ella is 8 years old. and given that is 4 years younger. then Lian is 12