x + y + 2z = 1 4x + 2y + z = 4 9x + 3y + z = 17 tlong d jwab yhaa.lengkap sesuai pertnyaannya di atas

x + y + 2z = 1 (× 1)
4x + 2y + z = 4 (× 2)

..x +... y + 2z = 1
8x + 4y + 2z = 8
------------------------ -
-7x - 3y = -7 =>pers.1

4x + 2y + z = 4
9x + 3y + z = 17
------------------------ -
-5x - y = -13 => pers.2

pers.1 => -7x - 3y = -7 (× 1)
pers.2 => -5x - y = -13 (× 3)

..-7x - 3y =.. -7
-15x - 3y = -39
---------------------- -
8x = 32
x = 32/8
x = 4

-7x - 3y = -7
-7(4) - 3y = -7
-28 - 3y = -7
-3y = -7 + 28
-3y = 21
y = 21/-3
y = -7

x + y + 2z = 1
4 + (-7) + 2z = 1
4 - 7 + 2z = 1
2z = 1 - 4 + 7
2z = 4
z = 4/2
z = 2

Jadi nilai x , y , dan z adalah 4 , -7 , dan 2