Respuesta :

For x = -1

[tex]f(-1)=4\times 7^{-1}=4\times \dfrac{1}{7^{1}}=\dfrac{4}{7}[/tex]


For x = 2

[tex]f(2)=4\times 7^{2}=4\times (7\times 7)=4\times 49=196[/tex]