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?

Respuesta :

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

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:

[tex]L-4=E[/tex] this gives [tex]L=E+4[/tex]

[tex]L+E=20[/tex]

Putting L=E+4 in the second equation

[tex]E+4+E=20[/tex]

[tex]2E=20-4[/tex]

[tex]2E=16[/tex]

So, [tex]E=8[/tex]

Now we have , L+E=20

[tex]L+8=20[/tex]

So, [tex]L=12[/tex]

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