(2x+y)^2-4x-2y-3=0怎么化简

(-2x+6y)的平方-(3x+2y)(2x-3y)+(-9y)*4怎么化简 3(x-y)-2(x+y)-5(x-y)+4(x+y)+3(x-y) 化简合并同类项 化简求值{(x=2y)(5x-2y)-(3x+2y)(3x-2y)]/4x,其中x=2,y=-1 初二化简求值题[（5x+2y)(3x+2y)+(x+2y)(x-2y)]/4x,其中x=2,y=3 [3x^2-(x+y)(y-x)][2(-x-y)(y-x)+2x^2+3y^2]怎么化简? 化简求值（4x-2y）-[-2（x-y）+（2x+y）]-4x，其中x=0，y=-3． 化简求值:[(x+y)(x-y)-(x-y)²+2y(x-y)]÷4y,其中x=二分之一,y=2 化简求值：(7x-2y)(3x-2y-1)-(4x+3y)(9x+6y),其中x=2,y=-1 已知3x^2+xy-2y^2=0,求{(x+y)/(x-y)+4xy/(y^2-x^2)}/{(x+3y)*(x-y)} 化简求值：已知x、y满足：x^2+y^2-4x+6y+13=0 求代数式 的值.(3x+y)^2-3(3x-y)(x+y 化简求值：已知x、y满足：x2+y2-4x+6y+13=0，求代数式（3x+y）2-3（3x-y）（x+y）-（x-3y {3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1