﹙-y﹚²·yⁿ-¹
问题描述:
﹙-y﹚²·yⁿ-¹
答
﹙-y﹚²·yⁿ-¹
=y²·yⁿ-¹
=yⁿ+¹
﹙-y﹚²·yⁿ-¹
﹙-y﹚²·yⁿ-¹
=y²·yⁿ-¹
=yⁿ+¹