已知x/y=4,则x²+xy+y²/x²-y²
=(x²/y²+x/y+1)/(x²/y²-1)
=(4²+4+1)/(4²-1)
=21/15;
=7/5;
很高兴为您解答,skyhunter002为您答疑解惑
如果本题有什么不明白可以追问,