15/(X+Y)=0.5 15/(X-Y)=3
解方程组:2(x+y)-3(x-y)=34(x+y)+3x=15+3y.
解方程x+y+(x+y/2)=15 3x+5y+4(x+y/2)=62
已知2x+2y=-8,4x+y=15求(x-y)^-(3x+2y)^
10/x+y+3/x-y=-5 15/x+y-2/x-y=-1(用换元法解此方程组)
解方程组 10(x-y)=3(x+y)+15 6(x+y)=4(2x-y)+16
3x-2y=15 3y-2x=11 求x+y
解方程组:{x+|3x-y|+3y=15 2x+y=6
x+x+x=15,x+y+y=19,求y-x等于几
已知方程组4x+3y=6,3x+4y=15,不解出x与y的值,求x+y/x-y的值
已知方程组4X+3Y=6和3X+4Y=15,不解出X,Y,求(X+Y)除以(X-Y)的值.
已知X-Y/X+Y=3,求代数式2(x-y)/X+Y-3X+Y/X+Y
已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y)