Question

y=(-1)^k + (-1)^k+1 é?

Answer 1

vejamos...

y=(-1)^k+(-1)^(k+1)

 desmembrar  (-1)^(k+1)=(-1)^k.(-1)^1=(-1)^k.(-1)

y=(-1)^k+(-1)(-1)^k
y=(-1)^k-(-1)^k

y=0