2x平方-x-1=0等于多少谢谢 2x平方+1=0，X等于多少
2x\u5e73\u65b9+x-1\u7b49\u4e8e0\u6c42\u5e2e\u5fd9\u56e0\u5f0f\u5206\u89e3\u6cd5
\u5982\u56fe
\u65e0\u56fe\u8bf7\u8ffd\u95ee
\u5982\u679c\u4f60\u8ba4\u53ef\u6211\u7684\u56de\u7b54\uff0c\u8bf7\u70b9\u51fb\u201c\u91c7\u7eb3\u56de\u7b54\u201d\uff0c\u795d\u5b66\u4e60\u8fdb\u6b65\uff01
\u624b\u673a\u63d0\u95ee\u7684\u670b\u53cb\u5728\u5ba2\u6237\u7aef\u53f3\u4e0a\u89d2\u8bc4\u4ef7\u70b9\u3010\u8bc4\u4ef7\u3011\uff0c\u7136\u540e\u5c31\u53ef\u4ee5\u9009\u62e9\u3010\u6ee1\u610f\uff0c\u95ee\u9898\u5df2\u7ecf\u5b8c\u7f8e\u89e3\u51b3\u3011\u4e86
\u8fd9\u9898\u6709\u95ee\u9898\uff0c2X\u5e73\u65b9\u4e0d\u53ef\u80fd\u7b49\u4e8e-1
2x²－x－1=0十字相乘法，得：
2 1
1 －1
则：
(2x＋1)(x－1)=0
x=1或x=－1/2
2x²-x-1=0
(2x+1)(x-1)=0
x= -1/2 , x=1
X=1或者X= -1/2
2x平方-x-1=0
2x^2-2x+x-1=0
(x-1)(2x+1)=0
x1=1
x2=-1/2
2x²-x-1=0
用十字相乘法得(2x+1)(x-1)=0
则x= -1/2 或=1
绛旓細(2x锛1)(x锛1)=0 x=1鎴杧=锛1/2
绛旓細2(x-1/4)²-9/8=0 (x-1/4)²=9/16 x-1/4= 卤3/4 x=1/4卤3/4 x=1鎴栬 x= -1/2
绛旓細瑙ｇ瓟锛2x²-x-1=0 x²-0.5x=0.5 x-0.5x+0.0625=0.5625 (x-0.25)²=0.5625 x-0.25=卤0.75 x=0.25卤0.75 x1=-0.5 x2=1
绛旓細锛2x-1锛夛紙x+1锛=0 鈭2x锕1=0鎴杧+1=0 鈭磝1=0.5 x2=锕1
绛旓細2x骞虫柟+x-1=0 4x骞虫柟+1=-8x 鐢ㄩ厤鏂规硶瑙ｈ杩囩▼ 璋㈣阿 鎴戞潵绛 2涓洖绛 #鐑# 濠氬Щ骞朵笉骞哥鐨勭埗姣,涓轰粈涔堜篃浼氬偓濠?宸﹁冲惉鍒板皬姣呯埍 2014-09-02 路 TA鑾峰緱瓒呰繃561涓禐 鐭ラ亾灏忔湁寤烘爲绛斾富 鍥炵瓟閲:910 閲囩撼鐜:100% 甯姪鐨勪汉:345涓 鎴戜篃鍘荤瓟棰樿闂釜浜洪〉 鍏虫敞 ...
绛旓細2X骞虫柟-X-1涓绛変簬0 2X²-X-1鈮0 (X-1)(2X+1鈮0 X1鈮1 X2鈮-1/2
绛旓細2x²锛2x锛1=0,(2x²锛2x+1/2)锛3/2=0,2(x²锛峹+1/4)锛3/2=0,2(x-1/2)^2锛3/2=0,(x-1/2)^2锛3/4=0,(x-1/2+鈭3/2)(x-1/2-鈭3/2)=0,x=1/2-鈭3/2鎴杧=1/2+鈭3/2
绛旓細2x骞虫柟-x=0 x(2x-1)=0 (鎻愬嚭涓涓獂,鍦ㄦ病鏈夊父鏁扮殑鎯呭喌涓嬪熀鏈兘杩欐牱)寰 x=0 2x-1=0 鎵浠 x1=0 , x2=1/2 绁濊韩浣撳仴搴 瀛︿範杩涙 甯屾湜閲囩撼璋㈣阿
绛旓細x²-x-1=0 x²=x+1 鎵浠³=x脳x²=x(x+1)=x²+x=(x+1)+x=2x+1 鎵浠ュ師寮=-(2x+1)+2(x+1)+2008 =-2x-1+2x+2+2008 =2009
绛旓細x³-2x+1=(x³+1锛-2x=(x+1锛夛紙x²-x+1)-2x. 鍥犱负x²-x=1.鎵浠ュ師寮=2x+2-2x=2.
