Question

Sebuah Bentuk Fungsi Rumus f(x) = ax + b, jika f(-3) = -16 dan f(5) = 32, Tentukan nilai f(7) !​

Answer 1

Penyelesaian:

f(x)=ax+b

f(-3)=-3a+b=-16

f(5)=5a+b=32

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-3a+b=-16

5a+b=32

-8a=-48

a=6

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f(5)=32

32=6(5)+b

32=30+b

b=2

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f(7)=6x+2

f(7)=6(7)+2

f(7)=42+2

f(7)=44

Answer 2

f(x) = ax + b

f ( - 3 ) = -3 ( a)x + b = -16

f ( -3 ) = -3ax + b = -16

f ( 5 ) = 5 ( a)x + b = 32

f ( 5 ) = 5ax + b = 32

______________

-3ax + b = -16

5ax + b = 32

___________-

-8a + 0 = -48

-8a = -48

a = -48 ÷ -8

a = 6

______________

F ( 5 ) = 32

32 = ax + b

32 = 6(5) + b

32 = 30 + b

32 - 30 = b

2 = b

b = 2

______________

f ( 7 ) = ax + b

f ( 7 ) = 6 ( 7 ) + 2

f ( 7 ) = 42 + 2

f ( 7 ) = 44