Skip to content / Đến nội dung
ThichHocToan.com

MathNet 2018-part-05 — 181 problems (EN–VI) Question 5

Math Olympiad Vault · MathNet 2018-part-05 — 181 problems (EN–VI)

Question 5

Prove that for every integer $n \ge 2$ one can find matrices $A_1, A_2, \dots, A_n \in \mathcal{M}_2(\mathbb{R})$, having non-zero entries, such that
$$
A_1^{-1} + A_2^{-1} + \dots + A_n^{-1} = (A_1 + A_2 + \dots + A_n)^{-1}.
$$