Diketahui fungsi f(x) =as + b,jika f (2) = -2 dan f (3) = 13,tentukan nilai f(4

f(x) = as+b
f(2)= 2a+b=-2
f(3)= 3a + b = 13
------------------------- -
-a = -15
a = 15
2a+b= -2
2.15+b=-2
30+b=-2
b= -32
f(4) = 15.4-32
= 28