①（11x+y)(11x-y)-(11x+y)²

3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27 (x-y)^2+7(x+y)-11(x-y)^2-8(x+y),先化简.再求值 已知x+y/y=11/8,求x-y/x+2y的值. {(x,y) |x|+|y| x>y?x:y 已知方程组2x-y=10,x+2y=11,求（2x-y)³-（2x-y）²（x-3y）的值 已知x+y/x=11/8,求x-y/x+2y的值 (2x-y)(y+2x)-2(3x+2y)(-2y-3x)-(11x-3y)*(2x+3y) 因式分解:x²(x-y)+(y-x) 已知4x²y-3y²=7,3x²y+4y²=19,求11x²y-2y& {x+y=5{3x-7y=11 化简：（x+y）+（2x+11×2y