3x+2y=7 5x-y=3 怎么算
(y-x)(x-y)^3(y-x)^5怎么算
已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y)
3x+2y=7 5x-y=3 怎么算
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
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
若(x-y)/(x+y)=3 则(x+2y)/(6x-7y)等于
(2x-3y)-(5x-y)怎么算
2x-y=8 3x+2y=5与3x+2y=1 3x-4y=-11用加减法怎么算?
(5*x+2*y)/(x+y)=3,求x与y的关系,是不是x=2y?怎么算?
x+y=3 x+2y=9 3/x+1=y y-x=3 y=2x-3 y-3x=1 2(x+1)-y=6 7x-5y=-9
{2x+y/3-2y=0 2(2x+y)-5=7y