jika a dan b penyelesaian dari 1/2a - 1/4b =2 dan 1/5a + 1/3b =6, nilai 2a - 3b adalah

semoga membantu :)
maaf kalau salah :"

1/2a - 1/4b = 2 dikali 2
a - 1/2b = 4
a - 3/6b = 4

1/5a + 1/3b = 6 dikali 5
a + 5/3b = 30
a + 10/6b = 30

a + 10/6b = 30
a - 3/6b = 4
-------------------- -
13/6b = 26
13b = 156
b = 12

1/2a - 1/4b = 2
1/2a - 1/4(12) = 2
1/2a - 3 = 2
1/2a = 5
a = 10

2a - 3b = 2(10) - 3(12)
= 20 - 36
= -16