soal fungsi Dirumuskan f(x)= ax + b. Jika f(4) = 19 dan f(2) = 7, Maka Bentuk fungsi Tersebut?

f(x)= ax + b

f(4)= 19 ==> 4a + b = 19
f(2)= 7 ==> 2a + b = 7

4a + b = 19
2a + b = 7
--------------- -
2a = 12
a = 12/2
a = 6

2a + b = 7
2.6 + b = 7
12 + b = 7
b = 7 - 12
b = -5

f(x)= ax + b
f(x)= 6x - 5