Question

II)    Dada a   função f(x ) =  3x  -  9,  determine.
 
1)     f(- 1 )                  3)   f( 3 )
 
2)     f( 0)                        4)  f(1/3)
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Answer 1

$f(x)=3x-9$

$f(-1)=3.(-1)-9\\f(-1)=-3-9\\f(-1)=-12$

$f(0)=3.0-9\\f(0)=0-9\\f(0)=-9$

$f(3)=3.3-9\\f(3)=9-9\\f(3)=0$

$f(\frac{1}{3})=3.\frac{1}{3}-9$

$f(\frac{1}{3})=\frac{3}{3}-9$

$f(\frac{1}{3})=1-9$

$f(\frac{1}{3})=-8$