Question

Dik fungsi f(x) = ax + b, jika f(2) = -5 dan f(-1) = 4 , maka nilai f(5) sama dengan?
Ada yang tau ⇧

Answer 1

2a + b = - 5
- a + b = 4
_________ -
3a = - 9
 a = - 3
 b = 1
f(x) = - 3x + 1
f(5) = - 15 + 1 = - 14

Answer 2

F(x) = ax+b
f(2) = 2a+b = -5
f(-1) = -1a+b = 4

maka
2a+b = -5
-1a+b = 4
______________-
3a    = -9
a = -3

2a+b = 5
2(-3) +b = -5
b = 1

maka f(5) = a(5)+b
              = -3(5)+1
             = -14