suatu fungsi F(x)=px+q diketahui F(1)=5 dan F(3)=-1. Nilai F(-1) adalah

langsung aja y

f(1) = p + q = 5
f(3) = 3p + q = -1
_____________-
-2p = 6
p = -3

p + q = 5
q = 5 - p
q = 5 - (-3)
q = 8

f(x) = px + q
f(x) = -3x + 8

maka
f(-1) = -3(-1) + 8
f(-1) = 3 + 8
f(-1) = 11

semoga berguna +_+