Diketahui rumus fungsi f(X) = ax + b jika f (5) = 16 f(4) = 11 hiunglah nilai f(-1)

F(x)= ax+b
f(5)= 5a+b =16
f(4)=4a+b = 11
_____________-
a=5
5a+b=16
5(5)+b=16
25+b=16
b=16-25
b=(-9)

f(-1)=5(-1)+(-9)
=-5+-9
=-14