diketahui sistem persamaan 8x + 3y = 12 dan 4x - 18y = 84. berapa nilai 2x-y? bantu dijawab yah :)

8x + 3y = 12
4x - 18y = 84

8x + 3y = 12
8x - 36y = 168
0 + 39y = -156
-y = -156 : 39
y = -4

4x - 18y = 84
4x - 18(-4) = 84
4x - (-72) = 84
4x + 72 = 84
4x = 84 - 72
4x = 12
x = 12 : 4
x = 3

maka

2x - y = 2(3) - (-4)

= 6-(-4)

= 10

8x + 3y = 12 x1 8x +3y = 12
4x - 18y = 84 x2 8x - 36y = 168

Gunakan subtitusi eliminasi
8x - 36y = 168
8x + 3y = 12 -
- 39y = 156
y = 156/-39
y = -4

8x + 3y = 12
8x + 3(-4) = 12
8x + (-12) = 12
8x - 12 = 12
8x = 12 + 12
x = 24/8
x = 3

2x - y = 2(3) - (-4)
= 6 + 4
= 10

Maaf kalau salah