Jawab:

12

Penjelasan dengan langkah-langkah:

Operasi Aljabar Fungsi

f(x) = x² – 2 ,  g(x) = 2x + 1 ,  h(x) = 2x – 3

CARA 1: Mencari (f – g – h)(6) dengan substitusi langsung

(f – g – h)(6) = f(6) – g(6) – h(6)

⇔ (f – g – h)(6) = 6² – 2 – [ 2(6) + 1 ] – [ 2(6) – 3 ]

⇔ (f – g – h)(6) = 36 – 2 – (12 + 1) – (12 – 3)

⇔ (f – g – h)(6) = 34 – 13 – 9

⇔ (f – g – h)(6) = 21 – 9

⇔ (f – g – h)(6) = 12

CARA 2: Mencari (f – g – h)(x) terlebih dahulu, kemudian substitusi

(f – g – h)(x) = f(x) – g(x) – h(x)

⇔ (f – g – h)(x) = x² – 2 – (2x + 1) – (2x – 3)

⇔ (f – g – h)(x) = x² – 2 – 2x – 1 – 2x + 3

⇔ (f – g – h)(x) = x² – 2x – 2x – 2 – 1 + 3

⇔ (f – g – h)(x) = x² – 4x – 3 + 3

⇔ (f – g – h)(x) = x² – 4x

x = 6

⇒ (f – g – h)(6) = 6² – 4(6) = 36 – 24

⇔ (f – g – h)(6) = 12