3a-b+2c=16 2a+b+c=1 4a-2b+c=18 Hitunglag 2a+b-3c Tolongf dibantu dongg kaka kaka,sekalian sama cara nya yaa makasihh

hai kak reyhan...aku bantu ya kak


2a+b+c=1
4a-2b+c=18
---------------- _
-2a + 3b = -17


3a-b+2c=16 (x1)
2a+b+c=1 (x2)
----------------

3a-b+2c=16
4a+2b+2c=2
----------------_
-a -3b = 14


-2a + 3b = -17
-a -3b = 14
----------------+
-3a = -3
a = 1

-a - 3b = 14
-1 -3b = 14
-3b = 15
b = -5

2a+b+c = 1
2-5+c = 1
c = 4

maka 2a + b - 3c = 2 - 5 -12 = -15

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