有几道数学题有点难,

题目

有几道数学题有点难,
1.已知x/5=y/3,则x/(x+y)+x/(x-y)-y²/(x²-y²)的值为________
2.（1）计算：1/(1-x)+1/(1+x)+2/(1+x²)+4/(1+x^4)
（2）猜想1/（1-x）+1/(1+x)+2/(1+x²)+4/(1+x^4)+…+1024/(1+x^1024)
3.已知abc=1,求a/(ab+a+1)+b/(bc+b+1)+c/(ca+c+1)的值

答案

1.已知x/5=y/3,则x/(x+y)+x/(x-y)-y²/(x²-y²)的值为________x/5=y/3x/y=5/3x/(x+y)+x/(x-y)-y²/(x²-y²)=x(x-y)/(x+y)(x-y)+x(x+y)/(x+y)(x-y)-y²/(x²-y²)=[x(x-y)+x(x...