Question

Jika 3x +4y = 36, 2x + z=16 dan 2y+ 3z= 36, maka nilai 5x+2y-2z adalah

Answer 1

3x +4y =36
4y+6z=72
_________  -
3x - 6z = -36

3x-6z=-36

{3x-6z=-36 }x(2)
{2x + z = 16} x 3

6x - 12z = -72
6x+3z = 48
___________ -
-15z = -120
z = 8

3x-6z =-36
3x- 6(8)=-36
3x-48 = -36
3x = 12
x=4

3x+4y = 36
3(4)+4y=36
4y=24
y=6

5x+2y-2z
= 5(4)+2(6)-2(8)
= 20+12-16
=16