Respostas

2013-09-27T11:01:53-03:00
f(x) = ax + b
f(3) = 3a + b = 5
f(2) = 2a + b = -5 .(-1)  

3a + b = 5
-2a-b = 5
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a = 10  

3a+b = 5
3.10 + b = 5
30 + b = 5 
b = 5 - 30
b = -25  

f(x) = 10x - 25
f(1/2) = 10.(1/2) - 25
f(1/2) = 5 - 25
f(1/2) = -20

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