a-(b-c)等于多少(定义简便方法)搜索 a-b-c =( )用简便方法计算
a-(b-c)\u7b49\u4e8e\u591a\u5c11(\u5b9a\u4e49\u7b80\u4fbf\u65b9\u6cd5)a-(b-c)\u7b49\u4e8ea-b+c
\u8bf7\u91c7\u7eb3\u6b63\u786e\u7b54\u6848\uff0c\u4f60\u4eec\u53ea\u63d0\u95ee\uff0c\u4e0d\u91c7\u7eb3\u6b63\u786e\u7b54\u6848\uff0c\u56de\u7b54\u90fd\u6ca1\u6709\u52b2\uff01\u8c22\u8c22\u7ba1\u7406\u5458\u63a8\u8350\u91c7\u7eb3\uff01\uff01
\u670b\u53cb\uff0c\u8bf7\u3010\u91c7\u7eb3\u7b54\u6848\u3011\uff0c\u60a8\u7684\u91c7\u7eb3\u662f\u6211\u7b54\u9898\u7684\u52a8\u529b\uff0c\u5982\u679c\u6ca1\u6709\u660e\u767d\uff0c\u8bf7\u8ffd\u95ee\u3002\u8c22\u8c22\u3002
\u7b80\u4fbf\u8ba1\u7b97
a-b-c
=a-(b+c)
\u4e5f\u53ef\u4ee5\u5148\u51cf\u53bbb\uff0c\u7136\u540e\u51cf\u53bbc
绛旓細鎮ㄥソ锛歔a-(b-c)]-[(a-b)-c]=a-b+c-a+b+c =2c 濡傛灉鏈鏈変粈涔堜笉鏄庣櫧鍙互杩介棶锛岃鍙婃椂鐐瑰嚮鍙充笅瑙掔殑銆愰噰绾充负婊℃剰鍥炵瓟銆戞寜閽 濡傛灉鏈夊叾浠栭棶棰樿閲囩撼鏈鍚庡彟鍙戠偣鍑诲悜鎴戞眰鍔╋紝绛旈涓嶆槗锛岃璋呰В锛岃阿璋傜瀛︿範杩涙锛
绛旓細瑙ｆ瀽濡備笅锛(a-b-c)²=a²-ab-ac-ab+b²+bc-ac+bc+c²=a²+b²+c²-2ab-2ac+2bc 骞虫柟鏄竴绉嶈繍绠楋紝姣斿锛宎鐨勫钩鏂硅〃绀篴脳a锛岀畝鍐欐垚a锛屼篃鍙啓鎴恆脳a(a鐨勪竴娆℃柟涔榓鐨勪竴娆℃柟绛変簬a鐨2娆℃柟锛夛紝渚嬪4脳4=16锛8脳8=64锛屽钩鏂圭鍙蜂负2銆傚垎鏁拌绠楁柟娉...
绛旓細A+锛圔-C锛=A+B-C 锛堟嫭鍙峰墠闈㈡槸鍔犲彿锛屽幓鎷彿锛屾嫭鍙烽噷闈笉鐢ㄥ彉鍙凤級
绛旓細-13-锛-17锛=4 鍦ㄦ湁姝ｈ礋鏁扮殑鍑忔硶杩愮畻涓紝鍑忓幓涓涓礋鏁帮紙锛17锛夛紝绛変簬鍔犱笂涓涓暣鏁帮紙17锛夛紝鎵浠ワ紝杩愮畻缁撴灉鏄4銆-13-锛堬紞17锛=-13+17 =4 姝ｈ礋鏁板姞鍑忔硶鍒 1銆佸悓鍙蜂袱鏁扮浉鍔狅紝鍙栫浉鍚岀殑绗﹀彿锛屽苟鎶婁粬浠殑缁濆鍊肩浉鍔犮2銆佷笉鍚屽彿涓ゆ暟鐩稿姞鍙栫粷瀵瑰艰緝澶х殑鏁扮殑绗﹀彿锛屽苟鐢ㄧ粷瀵瑰艰緝澶х殑鍑忓幓缁濆鍊艰緝...
绛旓細(a-b-c)鐨勫钩鏂 =a²-2a(b+c)+(b+c)²=a²-2ac-2ab+b²+2bc+c²
绛旓細9.鐜瀹氫箟涓绉嶆柊杩愮畻: ,鍒欍 10銆佺ぜ鍫傜涓鎺掓湁a涓骇浣,鍚庨潰姣忔帓閮芥瘮绗竴鎺掑1涓骇浣,鍒欑n鎺掑骇浣嶆湁 涓. 浜.缁嗗績閫変竴閫.(姣忛3鍒,鍏30鍒) 11.鈥滅宸炩濅簲鍙烽鑸规婚噸7790000鍏,淇濈暀涓や釜鏈夋晥鏁板瓧,鐢ㄧ璁版暟娉曡〃绀轰负( ) A銆 B銆 C銆 D銆 8 12. 宸茬煡2鏄叧浜嶺鐨勬柟绋3X+a=0鐨勪竴涓В,鍒...
绛旓細锛坅-b-c锛锛2 =(a-b)^2+c^2-2(a-b)c =a^2+b^2-2ab+c^2-2ac+2bc =a^2+b^2+c^2-2ab-2ac+2bc
绛旓細B
绛旓細浣犲ソ锛岃繖涓敤鐨勬槸瀹屽叏骞虫柟鍏紡锛(a-b-c)²=锛坅-b锛²-2c(a-b)+c²=a²-2ab+b²-2ac+2bc+c²寰堥珮鍏翠负鎮ㄨВ绛旓紝绁濅綘瀛︿範杩涙!鏈変笉鏄庣櫧鐨勫彲浠ヨ拷闂紒濡傛灉鎮ㄨ鍙垜鐨勫洖绛斻傝鐐瑰嚮涓嬮潰鐨勩愰変负婊℃剰鍥炵瓟銆戞寜閽紝璋㈣阿锛
绛旓細鐒跺悗鍐嶅湪宸﹀彸涓よ竟鍑忓幓a+b+c=6 鍙眰寰梒=0.1锛屼唬鍏+c=2.5 寰梑=2.4 鐒跺悗灏哻锛0.1鍜宐锛2.4 浠ｅ叆b-2c=2.2 鏁存暟鐨勫噺娉曟硶鍒欏垎涓夌鎯呭舰琛ㄨ堪锛1銆佷竴浣嶆暟鎴栦袱浣嶆暟鍑忓幓涓浣嶆暟锛岃屽樊鏄竴浣嶆暟鐨勫噺娉曟硶鍒欍傛牴鎹噺娉曟槸鍔犳硶鐨勯嗚繍绠楃殑鍏崇郴锛屽彲鍒╃敤鍔犳硶琛ㄦ潵璁＄畻銆2銆佸浣嶆暟鍑忔硶娉曞垯銆傛妸涓や釜澶氫綅...
