|x|=5,|y|=8,x/y
x+y=5; x^y+y^x=17
已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y)
(4x-2y-z)-{5x[8y-2y-(x+y)]-x+(3y-10z)]=? kuai
3x-2y=9 x-3y=2 x+y=5 x+2y=3 y=x 2x+y=8
已知x.x+y.y-6x-8y+25=0,求3x.x+5y的值
【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2=
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
(7y-3x)-(8y-5x)=
Y={X (-5
6(x-y)-2(x+y)=14 3(x-y)+(x+y)=5
3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27
解方程组(x+y)(x-2y)=-5 (x-y)(x+2y)=7