x²-5x+4=0x²-5x+4=0

怎么算啊这个：X²+4X+Y²-2Y+5=0 则X²+Y²=?²²²²²²²²²²²²X²+4X+Y²-2Y+5X=0 则X²+Y²=? 已知x²+4x+y²-2y+5=0,则x²+y²= 问几道有关分式的数学题 ,(1)[(5xy)/(x²+xy)]*[(xy+y²)/(2x²y²)]^3(2)[(x^3-3x+4)/(x²+2x-3)]÷[(x²-16)/(x²+6x+9)](3)(x²+x-3)/(x²+x-2)+1=(2x²+4x+1)/(x²+2x+1)(4)已知a²+4a+1=0 ,且(a^4+ x²-5x+4=0x²-5x+4=0 已知x²-5x-1=0,则x²+1/x²=?,x²/x&sup4+x²+1=? xy²/(x²y-y) × x²/(x²+x)=(x²-3x)/(x²-5x) × 2x-10/(x²-6x+9)=化简求植x²-1/(x²-x-2)除以x/2x-4,其中x=1/2[x-x/(x+1)]除以[x/(2x-4)] ,其中x=√2+1 a²b²x^4-（a^4+b^4)x²+a²b²=（ab≠0) 5(x²-x)=3(x²+x) -x²+4x-5 写过程（两步即可）答案 不要也行2/(x²-x)+3/(x²+x)=4/(x²-1)3/(x-1)+4x/(1-x²)=(-1)/(x+1)2/(x+1)+3/(x-1)=6/(x²-1)5/(x²+3x)-1/(x²-x)=0 已知x² -XY = 2,Y² -XY= 5,求x² - 4x Y+ Y² = 2x² + xY -3Y² = x² 已知x² -XY = 2,Y² -XY= 5,求x² - 4x Y+ Y² = 2x² + xY -3Y² = x² + xY- 2Y² =求x² - 4x Y+ Y² = 已知(x²+y²)(x²+y²-6)+9=0 ,求x²+y²的值. 若x²+xy-2y²=0,则x²+3xy+y²/x²+y² x²+xy-2y²=0则x²+3xy+y²/x²+y² 1·已知a+b+c=0且a²+b²+c²=1,求ab+bc+ac的值.2·已知x,y满足等式x²+y²-4x+y+17／4=0,求（x+y）²的值.3·已知x+y=5,x²+y²=13,求代数式x²y+2x²y²+xy²的值.4·若a²+b²+ x²-2x+y²+4y+5=0,求x²+2y的值 已知13x²-6xy+y²-4x+1=0,求(xy-x²)的5次方 (5/x²-3x-4)+(4/x²-5x-6)-(8/x²-10x+24)=?