himpunan penyelesaian x+2y =-3 y+2x=4 x+y+3z=8 adalah x,y,z nilai dari x+z adalah

cara dan jawaban terlampir

Metode Eliminasi

Pres 1 dan Pres 2

x + 2y = - 3 | x 2 |
2x + y = 4 | x 1 |

2x + 4y = - 6
2x + y = 4
__________ -
3y = - 10
y = - 10/3

Sibtusikan y = -10/3

x + 2y = - 3
x + 2(-10/3) = - 3
x + - 20/3 = - 3
x - 20/3 = - 3
x = - 3 + 20/3
x = - 9/3 + 20/3
x = 11/3

Pres 4

x + y + 3z = 8
11/3 + ( - 10/3 ) + 3z = 8
11/3 - 10/3 + 3z = 8
1/3 + 3z = 8
3z = 8 - 1/3
3z = 24/3 - 1/3
3z = 23/3
z = 23/9

x = 11/3
y = -10/3
z = 23/9

x + z
11/3 + 23/9
33/9 + 23/9 = 56/9 = 6 2/9