Question

F(x) = ax+b
F(2) = -1
F(-3) = 14
cari a,b?​

Answer 1

Jawaban:

Nilai a = -3

Nilai b = 5

Penjelasan dengan langkah-langkah:

Diketahui :

• f(x) = ax + b
• f(2) = -1
• f(-3) = 14

Ditanya :

• Nilai a dan b ?

Jawab :

f(x) = ax + b

f(2) = a(2) + b = -1

2a + b = -1 ... (i)

:\

f(x) = ax + b

f(-3) = a(-3) + b = 14

-3a + b = 14

b = 14 + 3a ... (ii)

Mencari nilai a :

Subsitusikan pers. (ii) ke pers. (i) :

2a + b = -1

2a + (14 + 3a) = -1

2a + 14 + 3a = -1

2a + 3a = -1 - 14

5a = -15

a = -15/5

a = -3

Mencari nilai b :

Subsitusikan a = -3 ke pers. (ii)

b = 14 + 3a

b = 14 + 3(-3)

b = 14 + (-9)

b = 14 - 9

b = 5