Diketahui sisitem persamaan tiga variabel X-y+z=3 2x+3y-z=27 3x-2y+3z=12 Tentukan nilai 5x-4y+2z

*diket :
x-y+z=3 (1)
2x+3y-z=27 (2)
3x-2y+3z= 12 (3)

*ditanya :
5x-4y+2z =?

*penjelasan
• eliminasi 1&2
x-y+z=3
2x+3y-z=27
= 3x+2y= 30 (4)

•eliminasi 2&3
2x+3y-z=27 |×3
3x-2y+3z=12 |×1
= 6x+9y-3z= 81
3x-2y+3z=12
= 9x+ 7y= 93 (5)

•eliminasi 4&5
3x+2y=30 |×7
9x+7y=93 |×2
= 21x+14y= 210
18x+14y= 186
= 3x= 24
x = 8

* 3x+2y = 30
3(8) +2y= 30
24+2y= 30
2y=30-24
2y=6
y = 3

* x - y + z = 3
(8)-(3)+ z = 3
z = -2

*5X-4Y+2Z
= 5(8)-4(3)+2(-2)
= 40-12-4
= 24