jika 3a+4b=36, 2a+c=16 dan 2b+3c =36 ,maka nilai dari 5a+2b-2c adalah

3a + 4b = 36... pers. 1
2a + c = 16.... pers. 2
2b + 3c = 36.... pers. 3

pertama eleminasi pers 1 dan 2
3a + 4b = 36 |×2|
2a + c = 16 |×3|
-----------------------
6a + 4b = 72
6a + 3c = 48
-------------------- (-)
4b - 4c = 24.... pers. 4

eleminasi pers. 3 dan 4
2b + 2c = 36 |×2|
4b - 4c = 24 |×1|
------------------------
4b + 4c = 72
4b - 4c = 24
----------------- (-)
8c = 48
c = 48/8
c = 6

subtitusi ke 2b + 2c = 36
2b + 2c = 36
2b + 2.6 = 36
2b + 12 = 36
2b = 36-12
2b = 24
b = 24/2
b = 12

lalu subtitusi ke 2a + c = 16
2a + c = 16
2a + 6 = 16
2a = 16-6
2a = 10
a = 10/2
a = 5

maka nilai dari 5a+2b-2c
5a+2b-2c = 5.5+2.12-2.6
= 25+24-12
= 25+12
= 37
semoga bermanfaat