jika 2x+3y = 13, 3x+2y=12, ax+by=13, dan -ax+by=5, nilai 2a-b =

persamaan linear 2 variable : x = 2 dan y = 3

ax + by = 13   ->   2a + 3b = 13
-ax + by = 5   ->   -2a + 3b = 5

lalukan persamaan variable lagi,,
a = 2 dan b = 3
sehingga :

2a - b = 2(2) - 3 = 4 - 3 = 1