若4x^2-4x+9y^2-12y+5=0求6x+2/3y已知多项式kx^2+8x+7分解为饮食后有一个因式是（2x+7）试求k=

已知X.x+y.y-4x+2y+5=0,求4X.X-12X Y+9Y.y的值 4(x-y)-3(x-y)=9 5(x-y)+2(x-y)=11 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-2y=5,则式子12-x+2y=.以知3x-4y=2x+y则x∶y= 3(x+y)-2(x-y)=11 4(x+y)+3(x-y)=9 3(x+y)+2(x-y)=36 4(x+y)-5(x-y)=2 x*x+2x+y*y-4y+5=0 x= y= 3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27 先化简再求值(x-y)(x-2y)+(x-2y)(x-3y)-2(x-3y)(x-4y) x=4 y=5 若4x^2-4x+9y^2-12y+5=0,求（x-3y）^2-(x+3y)^2 9(x-y)^2-12(x-y)+4=快 因式分解：4+12(x+y)+9(x-y)^2=? 已知x*x+4x+y*y-2y+5=0,则x*x+y*y=? (x-y)/4+(x+y)/5=1/4 (x+y)/9-(x-y)/3=//2(x-y)/4+(x+y)/5=1/4(x+y)/9-(x-y)/3=//2 若x^2+y^2+5/4=2x+y,求x^Y+y^x的值? 若5x+3y=3x+4y=x+2y+6,则x+y=___ 解方程组：x+y/2+x-y/3=6 4(x+y)-5(x-y)=12 接二元一次4(x+y)-3(x-y)=9;5(x-y)+2(x+y)=11