Question

Diketahui fungsi f(x) = ax + b. Jika f(-1) = 8 dan f(1) = 4, maka rumus fungsi f(x) adalah ...

Answer 1

F(x) = ax + b
f(-1) = 8
-a + b = 8 ..........(1)
f(1) = 4
a + b = 4 .........(2)

(1) dan (2)
-a + b = 8
a + b = 4
-----------------  -
-2a      = 4
   a       = -2

a + b = 4
-2 + b = 4
     b = 6

Rumus fungsi f(x) = -2x + 6

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Answer 2

F(x) = ax + b f(-1) = 8 f(1) = 4 -a + b = 8 a+ b = 4 Eliminasi a 2b = 12 b = 6 -a + b = 8 -a + 6 = 8 -a = 8 - 6 -a = 2 a = 2 Rumus fungsi f(x) = ax + b f(x) = -2x + 6