suatu fungsi f ditentukan dengan rumus f(x) = b+ax diketahui untuk f(-3) = 9 dan f(2) = -1 maka, nilai f(-8)=

f(x)=b+ax
f(-3) = b + a(-3) = 9
b - 3a = 9

f(2) = b + 2(a) = -1
b + 2a = -1

eliminasi
b - 3a = 9
b + 2a = -1
_________-
-5a = 10
a = -2

mencari nilai b
b - 3(-2) = 9
b + 6 = 9
b = 9-6
b = 3

nilai f(-8) = 3 + -2(-8)
= 3 + 16
= 19