若|2x-y+5|+(x+2y-4)的平方=0,则（2x-y)的三次方-（x-3y)(y-2x)的平方

若(x*x+y*y)(x*x+y*y)-4x*x*y*y=0,求代数式(x*x+5xy+y*y)/(x*x+2xy+y*y)的值 若x^2+y^2+5/4=2x+y,求x^Y+y^x的值? 若(x-y)乘(x+y)=5,(x+y)^2=4,试求x-y的值 若|x-2y+6|+(x+y+12)的2次方,求4x+5y {(z+y)(x-y)-(x-y)的2次方+2y(x-y)}除以4y [(x+y)(x-y)-(x-y)的平方+2y(x-y)]除以(4y)请帮我一下写两道计算题[(x+y)(x-y)-(x-y)的平方+2y(x-y)]除以(4y)[（3x+2y）（3x-2y）-（x+2y）（5x-2y）]除以（4x） 若|2x-y+5|+(x+2y-4)的平方=0,则（2x-y)的三次方-（x-3y)(y-2x)的平方 若x*x+4*y*y+2*x-4*y+2=0,求5*x*x+16*y*y的算术平方跟 若实数x、y满足x*x+y*y-2x+4y+5=0,求x-y的值 4x+2y-5x-y 因式分解(x-2y)(x-3y)+(x-4y)(x-5y)+（x-3y)(x-5y)+(x-2y)(x-4y) 若x=-1/4,能否确定代数式(2x-y)(2x+y)+(2x-y)(y-4x)+2y(y-3x)的值? 若X-Y分之X+2Y等于2,则代数式X-Y分之2（X+2Y)-X+2Y分之4（X-Y)的值为 若x-y/x+y=5,求x-y/2x+2y+5x+5y/3x-3y的值 若X=负四分之一,能否确定代数式(2X-Y)(2X+Y)+(2X-Y)(Y-4X)+2Y(Y-3X)的值? 若x+y分之x-y=3,求式子x+y分之5(x-y)—2(x-y)分之x+y的值 若x-y分之x+y=3,求式子x+y分之5(x-y)—2（x-y）分之x+y的值 已知X.x+y.y-4x+2y+5=0,求4X.X-12X Y+9Y.y的值