Diket:
pers 1: 5x - y - z = -13
5x - y + 13 = z
substitusi pers 1 ke pers 2:
3x - 2y + 3z = 6
3x - 2y + 3(5x - y + 13) = 6
3x - 2y + 15x - 3y + 39 = 6
18x - 5y = 6 - 39
18x - 5y = -33
substitusi pers 1 ke pers 3:
2x + y - z = -4
2x + y - (5x - y + 13) = -4
2x + y - 5x + y - 13 = -4
-3x + 2y = -4 + 13
-3x + 2y = 9 .... (kalikan -6)
18x - 12y = -54
eliminasi pers 2 dan pers 3,
18x - 5y = -33
18x - 12y = -54 -
7y = 21
y = 3
substitusi nilai y ke pers 3
-3x + 2y = 9
-3x + 2(3) = 9
-3x = 9 - 6
-3x = 3
x = -1
substitusi nilai x dan y ke pers 1
5x - y + 13 = z
5(-1) - 3 + 13 = z
-5 - 3 + 13 = z
5 = z
nilai dari 2xy + 3z = 2(-1)(3) + 3(5) = -6 +15 = 9
[answer.2.content]
