求10道难度较高的初一几何,因式分解数学题如题 谢谢了
\u521d\u4e00\u4e0b\u5b66\u671f\u6570\u5b66\u9898\uff08\u56e0\u5f0f\u5206\u89e3\uff09a^2+b^2+c^2+2ab+2bc+2ac
=a^2+2ab+b^2+2ac+2bc+c^2
=(a+b)^2+2c(a+b)+c^2
=(a+b+c)^2
1\u3001(14x-5+3x^2)\u00f7(x+5)
=(3x-1)(x+5)/(x+5)
=3x-1
2.\u300c(m+n)^2-4(m-n)^2\u300d\u00f7\uff083n-m)
=(m+n+2m-2n)(m+n-2m+2n)/(3n-m)
=(3m-n)(3n-m)/(3n-m)
=3m-n
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绛旓細1..濡傚浘锛屽湪闀挎柟褰BCD涓紝鈻矨BP鐨勯潰绉负20cm²锛屸柍CDQ鐨勯潰绉负35cm²锛屾眰闃村奖鍥涜竟褰㈢殑闈㈢Н銆2.濡傚浘锛屸垹A+鈭燘+鈭燙+鈭燚+鈭燚+鈭燛+鈭燜+鈭燝鐨勫害鏁颁负锛3.濡傚浘鎵绀猴紝宸茬煡ABCD涓洪暱鏂瑰舰锛孍鏄疌D涓婄殑涓鐐癸紝AE涓嶣C鐩镐氦浜嶧,涓擜B=8cm锛孌E=5cm锛屾眰鍥句腑闃村奖閮ㄥ垎鐨勯潰绉4.濡傚浘锛孉B//CD,...
绛旓細10宸茬煡螖ABC,鈭燘=60掳.AD,CE鏄骞冲垎绾,姹傝瘉:AE+CD=AC 鍏ㄧ瓑褰 4 1宸茬煡螖ABC鏄洿瑙掍笁瑙掑舰,AB=AC,螖ADE鏄洿瑙掍笁瑙掑舰,AD=AE,杩炴帴CD,BE,M鏄疊E涓偣,姹傝瘉:AM鈯D. 2宸茬煡螖ABC,AD,BE鏄楂,AD浜E浜嶩,涓擝H=AC,姹傗垹ABC. 3宸茬煡鈭燗OB,P涓鸿骞冲垎绾夸笂涓鐐,PC鈯A浜嶤,鈭燨AP+鈭燨BP=180掳,姹傝瘉:AO...
绛旓細24. (10鍒)濡傚浘17,鍦ㄢ柍ABC涓,AD涓衡垹BAC鐨勫钩鍒嗙嚎,DE鈯B浜嶦,DF鈯C浜嶧,鈻矨BC闈㈢Н鏄,AB=20鍘樼背,AC=8鍘樼背,姹侱E鐨勯暱.鍥涖佹嫇骞挎帰绱!(鏈ぇ棰樺叡22鍒)1.(10鍒)濡傚浘18,鍦ㄢ柍ABC涓,鐐笵鍦ˋB涓,BD=BE,(1)璇蜂綘鍐嶆坊鍔犱竴涓潯浠,浣垮緱鈻矪EA鈮屸柍BDC,骞惰鏄庣悊鐢,浣犳坊鍔犵殑鏉′欢鏄悊鐢辨槸:(2)鏍规嵁浣犳坊鍔犵殑鏉′欢,...
绛旓細灏嗛暱鏂瑰舰绾哥墖涓瑙掓姌鍙狅紝浣块《鐐笰钀藉湪F澶勶紝BC涓烘姌鐥曘傝嫢BE鏄垹FBD鐨勫钩鍒嗙嚎锛屾眰鈭燙BE銆傝В:鈭礏C涓烘姌鐥曪紝鈭粹垹CBF=1/2鈭燗BF 鍙堚埖鈭燜BE=1/2FBD,鈭粹垹CBE=鈭燙BF+鈭燜BE=1/2(鈭燗BF+鈭燜BD)=1/2*180掳=90掳
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绛旓細*3.45=2.3,BD=(2/3)*[3.45(鈭3)]=2.3(鈭3)鈻矨PD鑳戒负绛夎叞涓夎褰傚嵆AP=AD鏃躲傜敱浜庯細AB=6.9,AD=2.3(鈭3)鎵浠ワ細BP=AB-AD=6.9-2.3(鈭3)鎵浠ワ細PF/AC=BP/AB,鐢辨姹傚緱PF=3.45[(鈭3)-1]寰堢箒鐞愶紝鏍规嵁鍕捐偂瀹氱悊姹傚緱BF,浠庤屾眰鍑篎D,杩欐牱灏辫兘姹傚嚭PD鐨勯暱銆備綘鑷繁浣滀竴涓嬪惂銆