<span> 80/-40=-40/20=-2, the sequence: 80, -40, 20 is a geometric sequence its general formula is Vn+1 = q Vn, where q= -2, if we put </span>Vn+1 = f(x) <span> Vn = x
so we have f(x)= -2x so the graph that represents the sequence is graph of linear equation
