suatu fungsi ditentukan dengan rumus f(x) = ax+b jika f(3) = 1 dan f(-3) = -11 maka nilai a+b adalah

f(3) = a(3) + b
= 3a + b

f(-3) = a(-3) + b
= -3a + b

3a + b = 1
-3a + b = -11 (eliminasi)
6a = 12
a = 2

-3a + b = -11
-3(2) + b = -11
-6 + b = -11
-6 + 11 = b
-5 = b

f(3) = 3a + b = 1
f(-3) = -3a + b = -11
-------------------------
6a = 12
a = 2
f(3) = 3.2 + b = 1
= 6 + b = 1
= b = 1 - 6
b = -5

a + b = 2 + -5
= -3