3x/(x+1)(x+2)=A/(x+1)+B/(x+2),求实数A,B的值

来源:学生作业帮助网 编辑:作业帮 时间:2024/04/30 03:51:51
3x/(x+1)(x+2)=A/(x+1)+B/(x+2),求实数A,B的值

3x/(x+1)(x+2)=A/(x+1)+B/(x+2),求实数A,B的值
3x/(x+1)(x+2)=A/(x+1)+B/(x+2),求实数A,B的值

3x/(x+1)(x+2)=A/(x+1)+B/(x+2),求实数A,B的值
A/(x+1)+B/(x+2)
=[A(x+2)+B(x+1)]/(x+1)(x+2)
=[(A+B)x+(2A+B)]/(x+1)(x+2)
=3x/(x+1)(x+2)
所以(A+B)x+(2A+B)=3x
则A+B=3
2A+B=0
解得A=-3,B=6

3x/(x+1)(x+2)=A/(x+1)+B/(x+2),
3x/(x+1)(x+2)=(Ax+2A+Bx+B)/(x+1)(x+2)
3x/(x+1)(x+2)=[x(A+B)+2A+B]/(x+1)(x+2)
∴A+B=3 2A+B=0
∴A=-3
B=6

3x/(x+1)(x+2)=A(x+2)+B(x+1)/(x+1)(x+2)
3x/(x+1)(x+2)=(A+B)x+2A+B/(x+1)(x+2)
即A+B=3,2A+B=0,故A= -3 ,B=6

用待定系数法做

x^2-6x+5= A(x-2)(x-3)B(x-6)(x+1) a+x/x+1 ,x/x^2-2x-3 ,a/x^2+4x+3 *-----------------------------------------------*| 6 4 X | 8 X X | X X 5 || X X X | X X X | X 7 8 || X X X | X X X | X X X ||---------------+---------------+--------------- || X X X | X X X | 5 1 X || X X X | X 6 X | X X X || 8 X X | 3 5 X | 2 X X || 填九宫格帮帮忙.x x 6 x x 7 x x 98 x x x 3 x 1 x x 9 x x 6 x 5 x 3 x x x 3 x x x x 1 8x x x 9 x 1 x x x2 1 x x x x 6 x x x 6 x 7 x 3 x x 1 x x 9 x 2 x x x 47 x x 8 x x 5 x x (X+1)X(X+2)X(X+3)=504 七年级下册政治复习提纲(山东人民出版社)第五单元是 青春的脚步 青春的气息别弄错了啊!格式:X X X X X X X X X 1、X X X X X X X X X X.2、X X X X X X X X X.3、X X X X X X X X X X X. 一个“整式的乘法”的问题请先阅读下列解题过程,再仿做下面的问题.已知X*X + X - 1=0,求X*X*X + 2*X*X + 3的值.解X*X*X + 2X*X +3=X*X*X +X*X -X +X*X +X +3=X{X*X +X -1} +X*X +X -1 +4=0+0+4=4+ x + X*X + X*X*X=0.+ X*X + X*X*X 若A={x|(1/2)^(x+2)(x-3)>1}B={x|(3a-x)/(x-a) (x-3/x-2)-(x-2/x-1)=(x-5/x4) -(x-4/x-3) 解方程x/(x-2)=2x/(x-3)+(1-x)/(x-5x+6) x(x-2)-2x(x+1)-3x(x-5) 其中x=负½ x(x+1)+(x+2)+(x+3)+(x+4)+(x+5) = 27求x 请问这道题咋做 :(x)X (x+1) X (x+2) X (x+3) =360 已知集合M={x||x+1|+|x-3|>8},P={x|x^2+(a-8)x-8a 已知f(x+1)=x²-2x,则f(x)= A.x²-4x+3 B.x²-4x C已知f(x+1)=x²-2x,则f(x)=A.x²-4x+3 B.x²-4x C.x²-2x+1 D.x²-2x X+X+X+(X-1)+(X-2)+(X-3)+(X-4)=10(X-3)+(X-4) x+2/x+1-x+4/x+3=x+6/x+5-x+8/x+7 x=? x^4+x^3+x^2+x+1=0,x^2006+x^2005+x^2004+x^2003+x^2002