Diketahui fungsi f(x)= ax + b. Jika f(2) = -2 dan f (3) = 13, tentukan nilai f (4). . . .

f(x) = ax + b

f(2) = -2
2a + b = -2

f(3) = 13
3a + b = 13

2a + b = -2
3a + b = 13
------------------ -
-a = -15
a = 15

2a + b = -2
2(15) + b = -2
30 + b = -2
b = -2 - 30
b = -32

f(x) = 15x - 32

f(4) = 15(4) - 32
      = 60 - 32
      = 28