x+5/3+y+3/2=7 2x-3/5-y-2/3=0 求x、y值要简便运算,15分钟之内回答

已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) 3x+5y-(x+y)=6 2(x+y)-3x=-7 若2x-3y+4=0则x（x*x-1)+x(5-x*x)-6y+7 x+y=1 5x-2y=8 3x-y=7 2x-y=3x表示y和用y表示x x+y/2+x-y/6=5 2(x+y)-3(x-y)=-2 (x-y)/(x+y)=3求( 3x-2y-1)/(x+y-5) 3(x+y)+2(x-y)=36 4(x+y)-5(x-y)=2 化简:3(x-y)²-7(x-y)+ 2(x-y)²+5(x-y) 4(x-y)-3(x-y)=9 5(x-y)+2(x-y)=11 3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27 6(x-y)-2(x+y)=14 3(x-y)+(x+y)=5 计算(x^8-x^7y+x^5y^3-x^4y^4+x^3y^5-x^y^7+y^8)(x^2+xy+y^2) 先化简再求值(x-y)(x-2y)+(x-2y)(x-3y)-2(x-3y)(x-4y) x=4 y=5 化简:5(x-y)+2(x+y)-3(x-y) 把(x-y)看作一个整体,化解:5(x-y)+2(x-y)-4(x-y)= 3(x-y)把(x-y)看作一个整体,化解:5(x-y)+2(x-y)-4(x-y)=3(x-y)²-4(x-y)+7(x-y)-6(x-y)²= {(x+y)/2+(x-y)/3=1,(x+y)-5(x-y)=2.求x=?,y=? (2x+y)²+(x+3y)(x-3y)-x(5x+8y)因式分解 已知7x+5y/2y-x=3/2,且x≠0,求X/x-4y