Question

Suatu fungsi di rumuskan dengan f(x) = ax+b .jika f(-2)= -5 dan f(3) = 15, nilau f(8) adalah

Answer 1

F(x) = ax + b
f(-2) = -5 --> -2a + b = -5
f(3) = 15 --> 3a + b = 15 _
                       -5a = -20
                         a  = 4
3a + b = 15
3(4) + b = 15
b = 15 - 12
b = 3

f(x) = 4x + 3
f(8) = 4(8) + 3
     = 32 + 3
     = 35

semoga membantu :)

Answer 2

F(x) = ax + b

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

f(3) = 3a + b
15 = 3a + b............(2)

-5 = -2a + b
15 = 3a + b
_____________-

-20 = -5a
4 = a

15 = 3a + b
15 = 3(4) + b
b = 15 -12
b = 3

f(8) = 8a + b
= 8(4) + 3
= 32 + 3
= 35