diketahui rumus suatu fungsi f(3)=5, dan f(-1)=3.tentukan A.Nilai a dan b B.rumus fungsi f(x) C.maka nilai f(4) adalah...

A. nilai a dan b
dik
f(3) = 5
f(-1) = 3

maka
f(3) = 3a + b = 5
f(-1) = -a + b = 3
___________- eliminasi y
4a = 2
a = 2/4 atau a = 1/2

sub nilai a = 1/2 ke pers -a + b = 3 shingga
-1/2 + b = 3
b = 3 + 1/2
b = 7/2

B.rumus fungsi
f(x) = ax + b
f(x) = 1/2x + 7/2

C. nilai f(4)
f(4) = (1/2)(4) + 7/2
f(4) = 2 + 7/2
f(4) = 11/2