若3^x=27,2y=16,求x+y的值幂的乘方与积的乘方(六年级下数学)

若2/x-1/y=3,求[y/x-y/x-y(x-y/x-x+y)]/x-2y/x的值 已知x-y=3,求[（x+y)(x-y)-(x-y)^2+2y(x-y)]除以的值 y=3(x-y),x=2(x-y)求x,y的值 若x-y/x+y=5,求x-y/2x+2y+5x+5y/3x-3y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 解方程组：｛x：y=3：2 x-y=16求x、y的值 若x-y=2(x+y),求代数式x-y/x+y+x+y/x-y求代数式 x+y分之x-y+x-y分之x+y 已知:y=ax的3次方+bx+3,当x=-1/2时,y=-7,试求x=1/2时,y的值 若x-y=3,x^2-y^2=1,求x+y的值 若|x|=3,|y|=2,且x＞y,求x+y的值. 若／X+Y-9／+（2X-Y+3)=0求X与Y的值 若｜x｜=3,｜y｜=2,且｜x－y｜=y－x,求x+y的值. 若|x|=3,|y|=2,且|x-y|=y-x,求x+y的值 若|x|=3,|y|=2,且|x-y|=y-x,求x+y的值 若x*x-4y*y=-15,x+2y=3,求x和y的值 若X,Y互为相反数,且(X+Y+3)(X-Y-2)=0,求X,Y的值? 若x、y满足2x+y=6,x-3y=1,求7y(x-3y)²-2(3y-x)³的值 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