Question

Tolong selesaikan persamaan 3 variabel berikut: i. x + 2y + 3z = 4 ii. 2x + y - z = 3 iii. 3x + 3y + 2z = 7 dgn menggunakan metode substitusi, eliminasi-substitusi, atau determinan (pilih aja salah satu metodenya)

Answer 1

=> x + 2y + 3z = 4 (kali 1) x + 2y + 3z = 4
2x + y -z = 3 (kali 3) 6x + 3y - 3z = 9 +
_______________________________
7x + 5y = 13

=> x+2y+3z=4 (kali 2) 2x+4y+6z=8
3x+3y+2z=7 (kali 3) 9x+9y+6z=21 -
________________________________
7x-5y = -13

=> 7x + 5y = 13
7x - 5y = -13 -
______________
10y = 26
y = 26/10

=> 7x + 5(26/10) = 13
7x + 130/10 =13
7x = 13 - 13
x = 0

=> x+2y+3z=4
(0)+2(26/10) +3z = 4
0 + 42/10 + 3z =4
3z = 4 - 42/10
3z =-1/5
z = -1/5/3 = -3/5

HP = { 0, 13/5, -3/5}