2x+3y=-5,3x-4y=18的解

求5x-2y=x-y=4x-3y-2的解 先化简再求值(x-y)(x+y)-(x-2y) 的完全平方+x(3x-5y)-(x-y)(x-2y),其中x=1/2 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 3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27 二元一次方程组的解.2X-4Y=6 3X+2Y=172X+3Y=73X-5Y=13Y=X+52X+5Y=233X+5Y= 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) 1.已知:x-2y=3,求[(3x+2y)(3x-2y)-(x+2y)(5x-2y)]除4x 的值 已知x-2y=2011,求[(3x+2y)(3x-2y)-(x+2y)(5x-2y)]÷4x的值. 若x、y、z满足2x+3y+z=18,4x-3y+5y=24,求x+3y的值. 化简[(3x+4y)^2-(2x+y)(2x-y)+(-x+y)(5x-y)]除以-2y,其中x=-1,y=1 5x+6y+3x-4y+3-x+x =5x+3x-x+x+6y-4y+3 =8x=2y+3 谁能告诉我这题合并同类项的解 3(x+y)+2(x-y)=36 4(x+y)-5(x-y)=2 解方程组