Saya tamatan SDN.... Pertanyaan:: 1.Kucing (....) kg + kelinci (...) kg=10kg 2.kucing (....) kg + kambing (...) kg=24kg 3.kelinci (...) kg + kambing (...

misalkan
kucing = x
kelinci = y
kambing = z

maka
x + y = 10
x + z = 24
y + z = 20

x + y + z = ?

x + y = 10
x = 10 - y

Substitusikan
x + z = 24
10 - y + z = 24
-y + z = 14

Eliminasi
-y + z = 14
y + z = 20
------------------- +
2z = 34
z = 17

y + z = 20
y + 17 = 20
y = 3

x = 10 - y
x = 10 - 3
x = 7

x + y + z = 7 + 3 + 17 = 27 kg

jadi
Kucing 7 kg + kelinci 3 kg + kambing 17 kg = 27 kg

║SISTEM PERSAMAAN LINEAR TIGA VARIABEL║

[tex]\text{Misal Kucing = x , Kambing = y , Kelinci = z}\\\\\text{x + z = 10}\\\text{x + y = 24}\\\text{y + z = 20}\\\\\text{Eliminasi Pers I dgn II}\\\text{x + z = 10}\\\text{x + y = 24}\\\text{|||||||||| (-)}\\\text{y - z = 14}\\\\\text{Eliminasi lagi,,,}\\\text{y + z = 20}\\\text{y - z = 14}\\\text{|||||||||| (-)}\\\text{2z = 6}\\\text{z = 3 kg}\\\text{Kelinci = 3 kg}\\\\\text{Substitusi ...}\\\text{y = 14 + 3 = 17 kg}\\\text{Kambing = 17 kg}\\\\\text{Kucing = 24 - 17 = 7 kg}\\[/tex]

[tex]\boxed{\boxed{\,\text{Kucing + Kambing + Kelinci = 7 + 17 + 3 = 27 kg}}}[/tex]