Metode substitusi dari 2x + y = 9, x + 2y =3

2x + y = 9
. x + 2y =3 ( x 2 ) = 2x+4y=6
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2x + y = 9
2x +4y=6
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0 + 5y = 15

5y = 15
y = 15/5
y = 3

Maka

x + 2y = 3
x + 2 (3) = 3

x + 6 = 3

x = 3 -6

x = -3


Hasil akhirnya

x = -3 dan y = 3