(x+3y)/2=3/5与5(x-2y)=-4这题帮帮忙

已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) (3x+2y)+(5x-y)i=17-2i.求x与y 关于X,Y的方程组3X+2Y=2m+5与x-y=4m-5的解x,y满足x+2y x+y/2+x-y/6=5 2(x+y)-3(x-y)=-2 3(x+y)+2(x-y)=36 4(x+y)-5(x-y)=2 (x-y)/(x+y)=3求( 3x-2y-1)/(x+y-5) 已知关于x、y 的方程组x-y=a+3与2X+Y=5的解x、y满足x>0,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 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) {(x+y)/2+(x-y)/3=1,(x+y)-5(x-y)=2.求x=?,y=? 把(X-Y)和(X+Y)各看作一个字母因式,合并同类项3（X+Y)²-（X-Y)+2(X+Y)²+（X-Y)-5(X-Y)²=2在后面是²,2在前面是与后面相乘. 3x+y+5与2-4y+2x是同类项,求x,y 若｜x-y-5｜与｜2x+3y-15｜互为相反数,则x+y＝? 已知y-2与x+4成正比例 x=3 y=5,则y与x的关系 (2x-3y)-(5x-y)