Diketahui f (x) = ax + b ; jika f (1) = -2 Dan f (4) = 1, maka nilai f (2) adalah....

Kelas 8 Matematika
Bab Fungsi

f(x) = ax + b

f(1) = a + b = -2
f(4) = 4a + b = 1

4a + b = 1
  a + b = -2
--------------- -
3a = 3
a = 1

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

f(x) = x - 3
f(2) = 2 - 3
f(2) = -1