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8. e. 7x + 6
9. b. 4x – 6
10. c. 6
Penjelasan dengan langkah-langkah :
Operasi fungsi berlaku
- (f + g)(x) = f(x) + g(x)
- (f – g)(x) = f(x) – g(x)
- (f × g)(x) = f(x) × g(x)
- (f ÷ g)(x) = f(x) ÷ g(x)
Maka…
» No. 8 «
Diketahui
- f(x) = 2x + 5
- g(x) = 5x + 1
Ditanya
- (f + g)(x) …?
Jawaban
(f + g)(x) = f(x) + g(x)
(f + g)(x) = (2x + 5) + (5x + 1)
(f + g)(x) = 2x + 5x + 5 + 1
(f + g)(x) = 7x + 6
» No. 9 «
Diketahui
- f(x) = 9x + 2
- g(x) = 5x + 8
Ditanya
- (f – g)(x) …?
Jawaban
(f – g)(x) = f(x) – g(x)
(f – g)(x) = (9x + 2) – (5x + 8)
(f – g)(x) = 9x – 5x + 2 – 8
(f – g)(x) = 4x – 6
» No. 10 «
Diketahui
- f(x) = 9x + 2
- g(x) = 5x + 8
Ditanya
- (f – g)(3) …?
Jawaban
(f – g)(x) = 4x – 6 … (penyelesaian no. 9)
(f – g)(3) = 4(3) – 6
(f – g)(3) = 12 – 6
(f – g)(3) = 6