gunaka. metode substitusi! X - 3y = 7 2x + y = -7

Materi : SPLDV

METODE SUBSTITUSI
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x - 3y = 7
x = 7 + 3y

2x + y = -7
2(7 + 3y) + y = -7
14 + 6y + y = -7
14 + 7y = -7
7y = -7 - 14
7y = -21
y = -3

x = 7 + 3y
x = 7 + 3(-3)
x = 7 - 9
x = -2

Hp = {-3 , -2 }

x= 3y+7

2(3y+7)+y= -7
6y+ 14+ y= -7
7y= -7-14
7y= -21
y= -3

x-3(-3) = 7
x+9 = 7
x= -2