Question

Diketahui sistem persamaan linear 3x-2y=14 dan 2x+y=0. Nilai 3x-4y adalah...
a.-10
b.-6
c.6
d.22

Answer 1

3x-2y=14
3x=14-2y
x=(14-2y)/3.....*
2x+y=0....**
subsitusi...*ke..**
2(14-2y)/3+y=0
(28-4y)/3+y=0
28-4y+3y=0
28=y
x=(14-2×28)3=-14
3x-4y=3(-14)-4(28)=-42-112=-154

Answer 2

3x-2y = 14----> 3x-2y =14
2x+ y= 0 ------> 4x+2y = 0
____________________________ +
7x= 14
x=2


3x-2y = 14
-2y = 14-6
y = 8/-2
y= -4

3x-4y = 3.2 -4.-4
= 6 +16
=22