Fungsi g dinyatakan dengan rumus g(x) = ax + b. Jika g(5) = -21 dan g(-3) = 3, Maka g(7) = ..

g(5) --> 5a + b = -21
g(-3) --> -3a + b = 3
----------------------------- _
8a = -24
a = -3

5a + b = -21
5.-3 + b = -21
b = -21 + 15
b = -6

jadi, g(x) = -3x -6
g (7) = -3.7 -6 = -27