maka nilai f (5)adalah

Semoga membantu, maaf kalo salah:)

f(x) = px + q
f(3) = 3p + q = 15
f(1 ) = p + q = 7
------------------ -
2p = 8
p = 4

p + q = 7
4 + q = 7
q = 3

maka f(5)
f(x) = px + q
f(5) = 4(5) + 3
f(5) = 20 + 3
f(5) = 23