Diketahui f(x) = ax + b. Jika f(-1) = -8 dan f(2) =13, nilai f(5) =

f(-1) = -a + b = -8
f(2) = 2a + b = 13
eliminasi b
-a -2a = -8 - 13
-3a = -21
a = 7
subtitusi a
2a + b = 13
2.7 + b = 13
14 + b = 13
b = 13 -14 = -1

f(5) = 5.7 + (-1)
= 35 + (-1)
= 34