Fungsi f ditentukan olehf(x) = ax + b. jikaf(-3) = -15 dan f(3) = 9, maka nilai f(-2)+ f(2) adalah….

Jawaban:

-6

Penjelasan:

f(x) = ax + b

f(-3) = a(-3) + b

f(-3) = -3a + b

f(-3) = -15

-3a + b = -15

f(3) = a(3) + b

f(3) = 3a + b

f(3) = 9

3a + b = 9

eliminasi

-3a + b = -15

3a + b = 9

__________ –

-6a = -24

a = 4

substitusi

3a + b = 9

3(4) + b = 9

12 + b = 9

b = 9 – 12

b = -3

berarti,

f(x) = 4x – 3

nilai f(-2)

f(-2) = 4(-2) – 3

f(-2) = -8 – 3

f(-2) = -11

nilai f(2)

f(2) = 4(2) – 3

f(2) = 8 – 3

f(2) = 5

nilai f(-2) + f(2)

= -11 + 5

= -6