（x平方+y平方）算能用平方差公式分解因式的么？
(x+y)\u7684\u5e73\u65b9-(x-y)\u7684\u5e73\u65b9 \u7528\u5e73\u65b9\u5dee\u516c\u5f0f\u5206\u89e3\u56e0\u5f0f\u89e3\uff1a(x+y)^2-(x-y)^2
={(x+y)+(x-y)}{(x+y)-(x-y)}
=2x * 2y
=4xy
\u5229\u7528\u5e73\u65b9\u5dee\u516c\u5f0f\u5206\u89e3\u56e0\u5f0f
\uff08\u4e00\uff09x\u7684\u4e8c\u6b21\u65b9\uff08y-1\uff09+\uff081-y\uff09
=x²(y-1)-(y-1)
=(y-1)(x²-1)
=(y-1)(x-1)(x+1)
\uff08\u4e8c\uff09
\uff08a+2b\uff09\u7684\u5e73\u65b9-\uff08a-3b\uff09\u7684\u5e73\u65b9
=(a+2b-a+3b)(a+2b+a-3b)
=5b*(2-b)
\uff08\u4e09\uff09 \u5229\u7528\u56e0\u5f0f\u5206\u89e3\u8ba1\u7b97
1003*997
=(1000+3)(1000-3)
=1000000-9
=999991
2008\u7684\u5e73\u65b9-2007\u7684\u5e73\u65b9
=(2008-2007)(2008+2007)
=1*4015
=4015
\uff0856*\u4e8c\u5206\u4e4b\u4e09\uff09\u7684\u5e73\u65b9-\uff0843*\u4e00\u5206\u4e4b\u4e09\uff09\u7684\u5e73\u65b9
=(56*2/3-43*1/3)(56*2/3+43*1/3)
=69/3*155/3
=23*155/3
=3565/3
2.89*52\u7684\u5e73\u65b9-2.89*48\u7684\u5e73\u65b9
=2.89\u00d7(52²-48²)
=2.89\u00d7(52-48)(52+48)
=2.89\u00d7100\u00d74
=289\u00d74
=1156
\uff08\u56db)\u7ed9\u51fa\u4e09\u4e2a\u591a\u9879,X=2a\u7684\u5e73\u65b9+3ab+b\u7684\u5e73\u65b9\uff0cy=3a\u7684\u5e73\u65b9+3ab\uff0cZ=a\u7684\u5e73\u65b9+ab\uff0c\u8bf7\u4f60\u4efb\u9009\u8fde\u4e2a\u8fdb\u884c\u52a0\u6216\u8005\u51cf\u8fd0\u7b97\uff0c\u518d\u5c06\u7ed3\u679c\u5206\u89e3\u56e0\u5f0f\u3002
x+y+z
=2a²+3ab+b²+3a²+3ab+a²+ab
=6a²+7ab+b²
=(6a+b)(a+b)
不能用平方差公式分解因式。
可以按如下分解因式：
x²+y²
=x²+2xy+y² - 2xy
=(x+y)² - 2xy
=[x+y+√(2xy)] [x+y-√(2xy)]
不能
x^2+y^2=(x-y)^2+2xy
353
绛旓細濡傛灉鏄+鍙凤紝閭ｄ箞x²+y²涓嶈兘鍒嗚В 濡傛灉涓棿鏄-鍙凤紝閭ｄ箞鍙互鍒嗚В x²-y²=(x+y)(x-y)
绛旓細x骞虫柟+y骞虫柟 涓嶈兘鐢ㄥ钩鏂瑰樊鍏紡鍒嗚В鍥犲紡銆傚彲浠ユ寜濡備笅鍒嗚В鍥犲紡锛歺²+y²=x²+2xy+y² - 2xy =(x+y)² - 2xy =[x+y+鈭(2xy)] [x+y-鈭(2xy)]
绛旓細涓嶈兘
绛旓細涓嶈兘锛屽洜涓哄钩鏂瑰樊鍏紡鏄噺锛屼笉鏄姞锛
绛旓細杩欎釜涓嶈兘鍒嗚В鍟锛岄櫎闈炲湪澶嶆暟鑼冨洿鍐咃紝寮曞叆铏氭暟鍗曚綅i锛屾墠鑳藉垎瑙ｃ
绛旓細璇存槑锛鑳界敤骞虫柟宸鍒嗚В鐨勫紡瀛愮壒寰侊細1锛変袱椤癸紝绗﹀彿鐩稿弽 2锛変笉鐪嬬鍙凤紝涓ら」閮芥槸骞虫柟 鎵浠 x^2+y^2锛泋^2-y^2锛-x^2+y^2锛-x^2-y^2涓 绗竴涓拰绗洓涓紝涓ら」鐨勭鍙风浉鍚岋紝涓嶈 绗簩鍜岀涓変釜鍙互锛岀浜屼釜鍙互鍒嗚В涓锛坸+y)(x-y)绗笁涓彲浠ュ垎瑙ｄ负锛坹+x)(y-x)...
绛旓細鍥犱负(x+y)*(x-y)=x^2-y^2 鎵浠ワ紙x^2-y^2锛壝楋紙x^2+y^2锛壝楋紙x^4+y^4锛夆︼紙x^2n+y^2n锛=锛坸^4-y^4锛夛紙x^4+y^4锛夆︼紙x^2n+y^2n锛=x^2锛坣+1锛+y^2锛坣+1锛
绛旓細B. 璇曢鍒嗘瀽锛氭牴鎹钩鏂瑰樊鍏紡鐨勭壒寰:涓ゆ暟鍜屼笌杩欎袱鏁板樊鐩镐箻鍙娇鐢ㄥ钩鏂瑰樊鍏紡,褰㈠ .鍗冲彲寰楀嚭绛旀.骞虫柟宸叕寮忕殑鐗瑰緛鏄浉涔樼殑涓や釜浜岄」寮忎腑涓椤圭浉鍚,鍙︿竴椤逛簰涓虹浉鍙嶆暟.A. ,鏄剧劧涓嶈兘鐢ㄥ钩鏂瑰樊鍏紡,鏁呮湰閫夐」閿欒.B. ,鍥犺屽彲浣跨敤骞虫柟宸叕寮.C. 涓瓁銆亂涓嶇浉鍚,鏁呮湰閫夐」閿欒.D. 绗竴椤逛笉鐩...
绛旓細鍙互 鍘熷紡=(7xy)²-z²=(7xy+z)(7xy-z)
绛旓細鍥犱负骞虫柟宸叕寮忚姹備袱鑰呴兘鏄钩鏂规暟锛岃屽紡瀛愪腑绗簩涓獂鏄1娆★紝鎵浠涓嶈兘鐢ㄥ钩鏂瑰樊鍏紡鍒嗚В銆傝岀敤鎻愬彇鍏洜寮忓垎瑙ｃ
