已知(16^x+1 · 27^x-1)÷(2^3y+2 · 3^2y-5)=18
已知:3x=8y.求(1)x+y/y (2)2x+3y/x-2y
同底数幂的乘法已知:x(x-1)-(x^2-y)=1,求1/3(x-y)^3·(y-x)^2+5(x-y)[-(x-y)
(1)已知x+y=6,x²-y²=5,求x-y的值(2)若x+y=3,x²+y²
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=3分之1,y=二分之一,求代数式x-(x+y)+(x+2y)-(x+3y)+...-(x+13y)的值
已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y)
已知x-y=1,求[(x+2y)2+(2x+y)(x-4y)-3(x+y)(x-y)]÷y的值.
已知x+y+2(-x-y+1)=3(1-y-x)-4(y+x-1),则x+y等于( )
已知5|2x-3y+1|+(5x-2y-3)=0,求x,y的值
已知(x-2y)^2+|3x-1-2y|=0,求x+5y的值
已知(x+5y-20)^2+|2x-3y-1|=0,求x+y的值
1、已知x=2y,则x-5y/x+y=()