Question

Dada a função f (x)=3x - 6 ,calcule o valor de:
a) f (-3)=

b)f (0)

c)f (8)=

d) 1 sobre 5=

Answer 1

a) f(-3) = 3*(-3) - 6
                  -9 - 6
                      -15

b) f(0) = 3*0 - 6
                  -6

c) f(8) = 3*8 -6 
               24 -6 
                 18

d) f(1/5) = 3* 1/5 - 6
                   3/5 - 6
                      3 - 30 / 5
                         -27/5

Answer 2

Resolução da questão, veja:

Letra “A”:

$\mathsf{f(x) = 3x-6}}}~\to~\mathsf{f(-3)}}\\\\\\\ \mathsf{f(-3) = 3~\cdot~(-3)-6}}}\\\\\\\ \mathsf{f(-3) = -9-6}}\\\\\\\\\ \mathsf{\large\boxed{\boxed{\boxed{\boxed{\mathsf{f(-3) = -15.}}}}}}}}}}}}}}}$

Letra “B”:

$\mathsf{f(x) = 3x-6}}}~\to~\mathsf{f(0)}}\\\\\\\ \mathsf{f(0) = 3~\cdot~0 -6}}}\\\\\\\ \mathsf{f(0) = 0-6}}\\\\\\\ \mathsf{\large\boxed{\boxed{\boxed{\boxed{\mathsf{f(0) = -6.}}}}}}}}}}}}}}}$

Letra “C”:

$\mathsf{f(x) = 3x-6}}}~\to~\mathsf{f(8)}}\\\\\\\ \mathsf{f(8) = 3~\cdot~8 -6}}}\\\\\\\ \mathsf{f(8) = 24-6}}\\\\\\\ \mathsf{\large\boxed{\boxed{\boxed{\boxed{\mathsf{f(8) = 18.}}}}}}}}}}}}}}}}}}}}$

Letra “D”:

$\mathsf{f(x) = 3x-6}}}~\to~\mathsf{f(\frac{1}{5})}}}\\\\\\\ \mathsf{f(\frac{1}{5}}) = 3~\cdot~\dfrac{1}{5} -6}}}\\\\\\\ \mathsf{f(\frac{1}{5}}) = \dfrac{3}{5}-6}}\\\\\\\ \mathsf{f(\frac{1}{5}}) = \dfrac{3-30}{5}\\\\\\\\ \large\boxed{\boxed{\boxed{\boxed{\mathsf{f\bigg(\frac{1}{5}}\bigg) = \dfrac{-27}{5}}}}}}}}}}}}}}}}}}}}}}$

Espero que te ajude '-'