((13 x-x^2)/(x+1)) (x+(13-x)/(x+1))=42
来源:百度知道 编辑:UC知道 时间:2024/05/09 07:06:23
Solve ((13 x-x^2)/(x+1))*(x+(13-x)/(x+1))=42
燃烧№眼泪 把答案验算一下行不行?显然是错的.
燃烧№眼泪 把答案验算一下行不行?显然是错的.
设y=13-xx+1,则xy(x+y)=42,又xy+(x+y)=13x-x2x+1+x2+13x+1=13
∴xy,x+y是方程x2-13x+42=0的两个根,
解得x1=6,x2=7,即x+y=7xy=6或x+y=6xy=7
进而可得x1=1,x2=3+2,x3=3-
2
追答
x2=3+根号2:x3=3-根号2
((x(13-x)/(x+1)*(x+(13-x)/(x+1))=42x
x*(13-x)/(x+1)*(x+1)=42
13x-x^2=42
x=7 x=6
分解因式,分解为
(x-6)(x-1)((x-6)x+7)=0
这样就好解了
((13 x-x^2)/(x+1)) (x+(13-x)/(x+1))=42
解方程(X-2)/(X+3)=1-(2X-13)/(X^2-9)
x^2+x+1=2/(x^2+x)
[x+2]/[x+1]-[x+4]/[x+3]-[x+3]/[x+2]+]x+5]/[x+4]
x+x^2+x^3+x^4+x^5+...+x^12=500/12
x-1/x^2+3x+2+6/2+x-x^2-10-x/4-x^2
(x^2+2x-3)/(x^2-9)*(x^2-5x+6)/(3x^2-x-2)
x/(x-2) (x-2)/x (2x-8)/x(x-2)=0
x+ 1/x =√13 ,求(1) x^2+ 1/(x^2) (2)x-1/(x^2)
1/x-1 +1/(x-1)(x-2)+1/(x-2)(x-3)+1/(x-3)(x-4)+1/(x-4)(x-5)