3^x=4,3^y=5,求3^3x+2y+1-(3^x+y)^2

已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) 已知x=1/3,y=-1/2,求代数式x-(x+y)+(x+2y)-(x+3y)+(x+4y)-(x+5y)+...-( 已知X-Y/X+Y=3,求代数式2(x-y)/X+Y-3X+Y/X+Y 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 {3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1 3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27 已知：3x=8y.求（1）x+y/y (2)2x+3y/x-2y 若2x-3y=0,求5x+4y/3x-2y 求5x-2y=x-y=4x-3y-2的解 2^x=4^(y-1) 27^y=3^(x+1)求x-y 方程式计算5X-2=Y 4X+3=Y 求X.Y