( )^2 - a^2 - b^2 - c^2 = -2ab-2ac+2bc
问题描述:
( )^2 - a^2 - b^2 - c^2 = -2ab-2ac+2bc
答
(a-b-c)^2 - a^2 - b^2 - c^2 = -2ab-2ac+2bc
( )^2 - a^2 - b^2 - c^2 = -2ab-2ac+2bc
(a-b-c)^2 - a^2 - b^2 - c^2 = -2ab-2ac+2bc