{ 2x+3y=7,3x-4y=2怎么解

{ 2x+3y=7,3x-4y=2怎么解 数学 {x/3-y/4=-1 3x-2y=-7 方程组 怎么解 已知实数x.y满足根号(x+y-8)+根号(8-x-y)=根号(3x-y-4)+根号(x-2y+7),求x,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 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 (x+y)(x+2y)(x+3y)(x+4y)=-40 这题怎么解?X-Y=4,2X+Y=20,X=?Y=?3X+2Y=14,2X-3Y=5,X=?Y=? 已知X-Y/X+Y=3,求代数式2(x-y)/X+Y-3X+Y/X+Y