1. fungsi f : x —> ax + b, jika f (-1) = -9 dan f (2) = 3 maka tentukan :

Penjelasan dengan langkah-langkah:

f(x)= ax + b

f(-1) = a(-1) + b

-9 = -a +b

f(2) = a(2) + b

3 = 2a + b

-a + b = -9

2a + b = 3 –

-3a = -12

a = -12/-3

a = 4

-a + b = -9

-(4) + b = -9

b = -9 + 4

b = -5

a) nilai a = 4 dan nilai b = -5

b) rumus fungsi

f(x) = ax + b

f(x) = 4x – 5

c) nilai f(5)

f(5) = 4x – 5

f(5) = 4(5) – 5

f(5) = 20 – 5

f(5) = 15