Question

3 – Qual é a razão da PG (-2, 4, -8, 16, -32,...) ?
a) -1 b) 2 c) -2
d) 4 e) ½

Answer 1

$Sendo\\ \\ a_1=-2\\ a_2=4\\ a_3=-8\\ \\ r=q=a_2\div a_1=a_3\div a_2\\ 4\div(-2)=(-8)\div4)\\ -2=-2\\ \\ Logo~~ r=-2~~letra~~c$