-5(x-2y)^20 -4(5x-13y)^39 +3(5x-13y)^39 -20(x-2y)^20 其中 x=5
-5(x-2y)^20 -4(5x-13y)^39 +3(5x-13y)^39 -20(x-2y)^20 其中 x=5
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
化简[(3x+4y)^2-(2x+y)(2x-y)+(-x+y)(5x-y)]除以-2y,其中x=-1,y=1
化简(x+y)-(2x+y/2)-(3x+y/6)-(4x+y/12)-(5x+y/20)-……-(10x+y/90)
[(x+2y)²-(x+y)(3x-y)-5y²]÷(2x),其中x,y满足x²+4x+y
已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y)
先化简再求值:(3x-y)^2-(2x+y)^2-5x(x-y),其中x=20,y=1
(2x+y-1)(2x-y+1)-(3x+y)(3x-y),其中x=5分之1,
3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27
化简求值{(x=2y)(5x-2y)-(3x+2y)(3x-2y)]/4x,其中x=2,y=-1
先化简,再求值:[(5X+2Y)(3X+2Y)+(X-2Y)(X+2Y)]/4X,其中X=2,Y=-3
初二化简求值题[(5x+2y)(3x+2y)+(x+2y)(x-2y)]/4x,其中x=2,y=3