diketahui suatu fungsi f(x)=ax + b.jika f(1)=-2 dan f(5)=2,maka nilai a+b adalah.... A)4 B)2 C)-2 D)2 (TOLONG DIJAWAB)

f(x) = ax + b
f(1) = a.1 + b
-2 = a + b ••• (1)
f(5) = a.5 + b
2 = 5a + b ••• (2)

a + b = -2
5a + b = 2
--------------- -
-4a = -4
a = 1

a + b = -2
1 + b = -2
b = -3

Maka,
a + b
= 1 + (-3)
= -2
Jawaban : C