(x-y)²=多少？ (-x-y)的平方等于多少
(x-y)^3=(x-y)^3
=(x-y)(x-y)²
=(x-y)(x²-2xy+y²)
=x(x²-2xy+y²)-y(x²-2xy+y²)
=x³-2x²y+xy²-x²y+2xy²-y³
=x³-3x²y+3xy²-y³
\u795d\u5b66\u4e60\u8fdb\u6b65\uff0c\u671b\u91c7\u7eb3~~
\u4e0d\u61c2\u7684\u6b22\u8fce\u8ffd\u95ee~~
\u89e3\uff1a(\u4e00x\u4e00y)^2
=[\u4e00(x\u5341y)]^2
=(\u4e001)^2(x\u5341y)^2
=(x\u5341y)^2
=x^2\u53412xy\u5341y^2
（x-y）（x-y）
（x+y）x（x-y）
x平方-2xy+y平方
绛旓細锛坸-y锛²=x²-2xy+y²~鍥炵瓟瀹屾瘯~~缁撴灉浠呬緵鍙傝儈~\(^o^)/~绁濆涔犺繘姝~~
绛旓細瀹屽叏骞虫柟鍏紡
绛旓細(x-y)*(x+2y)=x²-2xy-xy-2y²=x²-3xy-2y²^__^鐪熷績绁濅綘瀛︿範杩涙锛屽鏋滀綘瀵硅繖涓瓟妗堟湁浠涔堢枒闂紝璇疯拷闂紝鍙﹀濡傛灉浣犺寰楁垜鐨勫洖绛斿浣犳湁鎵甯姪锛岃鍗冧竾鍒繕璁伴噰绾冲摕锛
绛旓細锛坸-y)鐨勫钩鏂=锛坸-y)(x-y)=x骞虫柟-xy-xy+y骞虫柟=x骞虫柟-2xy+y骞虫柟 杩欐槸瀹屽叏骞虫柟鍏紡锛岋紙x+y锛夌殑骞虫柟鍙鍦2xy鍓嶉潰鏀规垚+灏辫浜
绛旓細鎮ㄥソ锛锛坸-y锛²脳锛坹-x锛³=锛坹-x锛²脳锛坹-x锛³=锛坹-x锛夌殑5娆℃柟 涓嶆槑鐧斤紝鍙互杩介棶濡傛湁甯姪锛岃寰楅噰绾 濡傝拷鍔犲叾瀹冮棶棰橈紝閲囩撼鏈鍚庡彟鍙戝苟鐐瑰嚮鍚戞垜姹傚姪锛岃阿璋 绁濆涔犺繘姝ワ紒
绛旓細(x-y)(x鍗亂)⁶x⁴y³锛屽彲浠ユ槸鍓嶉潰x涓庡悗闈³y³鐨勭Н锛屽姞鍓嶉潰-y涓庡悗闈⁴y²椤圭殑绉傜郴鏁版槸 C(6,3)-C(6,2)=6.5.4/(1.2.3)-6脳5/(1脳2)=20-15=5
绛旓細瑙ｇ瓟锛氬綋鐒舵槸姝ｇ‘鐨勶紝鍥犱负鍏堝埄鐢ㄦ彁鍙栧叕鍥犲紡娉曞緱鍒(x-y)(x-y)锛岃屽湪鍥犲紡鍒嗚В鐨勭粨鏋滃綋涓紝鐩稿悓鐨勫洜寮忚鐢ㄥ箓鐨勫舰寮忔潵琛ㄧず锛屽嵆(x-y)^2锛屾晠缁撴灉鏄纭殑銆
绛旓細(x-y)²=(x-y)(x-y)=x²-xy-xy+y²=x²-2xy+y²
绛旓細杩欐槸鍒濅腑鐨勪簩鍏冩柟绋嬪叕寮忥紝绛旀濡備笅 =锛坸-y锛²=x²-2xy+y²
