分式的加减(3)

来源:学生作业帮助网 编辑:作业帮 时间:2024/05/09 02:06:44
分式的加减(3)

分式的加减(3)
分式的加减(3)
 

分式的加减(3)
x^2-y^2=(x+y)*(x-y)=2(x-y)=16
故有x-y=8,x+y=2.
解得x=5,y=-3
原式=3(x-y)/(y+x)(y-x)+(x-y)^2/(x-y)(x+y)-(x-3)(x+2)/(x+2)*1/(x+y)
=-3/(x+y)+(x-y)/(x+y)-(x-3)/(x+y)
=(-3+x-y-x+3)/(x+y)
=-y/(x+y)
=-(-3)/2
=3/2

解得X=5,Y=3,原式=3/(-x-y)+(x-y)/(x+y)-(x-3)=1.5

带进去啊