Kakk di bantu dongg
Jawab:
NOMOR 1
f(x) = ax + b
f(2) = 2a + b
f(2) = -2
Maka,
2a + b = -2
f(3) = 3a + b
f(3) = 13
Maka,
3a + b = 13
Kita cari nilai a dan b,
2a + b = -2
b = – 2 – 2a
Maka,
= 3a + ( -2 -2a ) = 13
= 3a – 2 – 2a = 13
= a – 2 = 13
= a = 15
= 2a + b = -2
= 2(15) + b = -2
= 30 + b = -2
= b = -32
Maka,
(A)
a = 15
b = -32
(B)
Persamaannya adalah,
f(x) = 15x – 32
(C)
f(4) = 15(4) – 32 = 60 – 32 = 28
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NOMOR 2
Diketahui f(x) = 3x – 2
A.) x = 2
= f(2) = 3(2) – 2 = 6 – 2 = 4
B.) f(a) = -5
= f(x) = 3x – 2
= f(a) = 3a – 2
= 3a – 2 = -5
= 3a = -3
= a = -1