f (1) = 4 f (2) = 3 tentukan nilai A dan B menggunakan cara eliminasi dan subsitusi

Elminasi
a + b = 4
2a + b = 3
---------------- -
       -a = 1 <--> a = -1
Subtitusi a = -1
-1 + b = 4 <-> b = 5

Misal:
f(x) = ax + b
a + b = 4
2a + b = 3
________ -
- a = 1
a = - 1
b = 5
f(x) = - x + 5