当x=3,y=2.5时,3x+4y=(),6x—3y=().

当2x-y/x+y=3时,求代数式2x-y/2x+2y+x+y/6x-3y的值. 当2x-y\x+y=3时,求代数式2x-y/2x+2y+x+y/6x-3y的値. 当2x-y/x+y=3时,求代数式2x-y/6x-3y的值 1.已知二元一次方程3X+4Y=6,当X,Y互为相反数,X=?Y=?当X与Y相等,X=?Y=? 对于等式y=⅓x+6,x满足条件时,y>4;y₁=x+3,y₂=-x+1.当y x+y/2+x-y/3=6,4(x+y)-3(x-y)=-20 {(x+y)/2+(x-y)/3=6 4(x+y)-3(x-y)=-20 4(x+y)-3(x-y)=-20,2/x+y+3/x-y=6 {3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1 ｛4/(x+y)+6/(x-y)=3 ｛9/(x-y)-1/(x+y)=1 指数函数y=3^x当x 1、当(x+y)/（x-2y）=3时,2x/y=?