dik f (x)=ax+b f (2)=3dan f (4)=11.tentukan nilai a dan b .tentukan rumus f (x) please kak jawab pakai cara .besok mau dikumpulin

Jawab=

f (x)= ax+b
f (2)= 2a+b= 3
f (4)= 4a+b= 11
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-2a = -8
a = 4

2a+b = 3
2 (4)+b = 3
8 + b = 3
b = 3-8
b = -5

Rumus f (x) = f (x)= ax+b
f (x)= 4x+(-5)
atau 4x-5