7x-5y=3 3x+y=5 x=?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(x-y)(x+y)-(x-2y) 的完全平方+x(3x-5y)-(x-y)(x-2y),其中x=1/2 y
(5x+3y)(3y-5x)-(4x-y)(4y+x)=
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
已知x/5=y/3,则(x/x+y)+(y/x-y)-(yxy/xxx-yxy)
|x|=3 |y|=5 |x-y|=|x|+|y| 求 X+Y和 X-Y 等于多少
化简[(3x+4y)^2-(2x+y)(2x-y)+(-x+y)(5x-y)]除以-2y,其中x=-1,y=1
y-x=3 7x+5y=-9
{x+y=5{3x-7y=11
(7y-3x)-(8y-5x)=
{y=x+3,7x+5y+9;