Question

Dada a função f(x) = -2x +1, o valor de f(1/3) + f (4/7) é igual a:
a) 4/21
b) 1/21
c)-3/21
d) -2/21
e) 2/21

Answer 1

f(1/3)=-2*1/3+1
f(1/3)=-2/3+1
f(1/3)=1/3

f(4/7)=-2*4/7+1
f(4/7)=-8/7+1
f(4/7)=-1/7

f(1/3) + f(4/7) = 1/3-1/7=4/21

Answer 2

f(x) = -2x +1

f(1/3) = -2 * 1/3 +1
f(1/3) = -2/3 +1
f(1/3) = 1/3

f (4/7) = -2*4/7 +1
f (4/7) = -8/7 +1
f (4/7) =  -1/7

f(1/3) + f(4/7)
1/3 - 1/7
(7 - 3)/21
4/21 <<<<< Resposta: Alterantiva A<<<<