Question

Diketahui : f(X) = ax +b jika f(7) = 6 dan f(8) = 1 , tentukan nilai a dan b serta f(-2) , mohon dibantu ya trmksh

Answer 1

F(x) = ax + b
f(7) = 7a + b = 6
f(8) = 8a + b = (-2)
-----------------------(-)
-a = 8
a = -8
7a + b = 6
7(-8) + b = 6
b = 6 + 56 = 62
f(x) = -8x + 62
f(-2) = (-8)(-2) + 62 = 46

Answer 2

F(x) = ax + b

f(7) = a (7) + b = 7a + b = 6
f(8) = a (8) + b = 8a + b = 1 - 
                           - a     = 5
                             a     = -5

7a + b = 6 --> 7 (-5) + b = 6 --> -35 + b = 6 --> b = 41

f(-2) = ax + b = -5 (-2) + 41 = 51