Question

-2x+3y-2z=3
4x+2y-z=9
4x-8y+2z=-6

tolong + caranya ya?

Answer 1

Verified answer

Jawab

eliminasi z
-2x + 3y - 2z = 3
4x + 2y -z = 9 .......kali 2

-2x + 3y - 2z = 3
8x + 4y - 2z = 18...(-)
-10 x - y = - 15....(I)

-2x + 3y - 2z = 3
4x - 8y + 2z = - 6 ...(+)
2x - 5y = - 3 ...(ii)

(i) dan (ii)
-10x - y = -15
2x - 5y = - 3.......kali 5

-10x - y = - 15
10x - 25y = - 15....(+)
- 26y = -30
y = 30/26 = 15/13

2x- 5y = - 3
2x= - 3 + 5y
2x = - 3 + 5(15/13)
2x = -39/13 + 75/13
2x= 36/13
x= 18/13

-2x + 3y - 2z = 3
-2(18/13) +3(15/13)- 2z= 3
 36/13+ 45/13 - 2 z= 3
71/13 - 2z= 3
2z= 71/13 - 3= 71/13 - 39/13
2z = 32/13
z = 16/13
(x,y,z)= (18/13  , 15/13 , 16/13)