Diketahui f(x) = 4x - 1. jika f(a) = -12 dan f(b) = 35 maka nilai dari a + b adalah... A.-5 B.-4 C.4 D.9

Mapel : Matematika

Kelas : 10

Bab : Relasi dan Fungsi
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f(x) = 4x - 1

f(a) = -12

f(b) = 35


Ditanya → a + b

Penyelesaian :
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f(a) = -12

4x - 1 = - 12

4x = -12 + 1

4x = -11

x = -11/4 → a = -11/4

_______________

f(b) = 35

4x - 1 = 35

4x = 35 + 1

4x = 36

x = 36/4

x = 9 → b = 9


Sehingga,

= a + b

= -11/4 + 9

= -11/4 + 36/4

= (-11 + 36)/4

= 25/4

= 6 ¼ → opsi jawaban Tidak ada

f(x) = 4x - 1
f(a) = -12
f(b) = 35
a + b = ?

f(x) = 4x - 1
=> f(a) = 4(a) - 1
=> -12 = 4a - 1
=> 4a = -11
=> a = -11/4

f(x) = 4x - 1
=> f(b) = 4(b) - 1
=> 35 = 4b - 1
=> 4b = 36
=> b = 36/4
=> b = 9

a + b = -11/4 + 9
a + b = 25/4
a + b = 6 1/4

Semoga membantu :)