Question

dada a função f:IR→IR, defina por f(x) = -6x +15. calcule
a, f(-3)
b, f(x) (1/3)
c, f(3)

Answer 1

Para calcular esses valores, basta substituirmos x nos itens.

f(x) = -6x+15

a) f(-3) = -6•(-3)+15
f(-3) = 18+15

f(-3) =33

b) f(1/3) = -6•(1/3)+15
f(1/3) = -2+15

f(1/3) = 13

c) f(3) = -6•(3)+15
f(3) = -18+15

f(3) = -3

Answer 2

Ola Marcio 

f(x) = -6x + 15

f(-3) = 18 + 15 = 33

f(1/3) = -2 + 15 = 13 

f(3) = -18 + 15 = -3