4x-15y=17=20 6x-25y-23=-16
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
解方程组 10(x-y)=3(x+y)+15 6(x+y)=4(2x-y)+16
已知x的平方+y的平方-8x+6y+25=0,求(x-y+4xy/x-y)(x+y-4xy/x+y)
已知x²+y²-8x+6y+25=0,求(x-y+4xy/x-y)(x+y-4xy/x+y)
已知x.x+y.y+8x+6y+25=0,求代数式(x.x-4y.y)/(x.x+4xy+4y.y)-x/(x+2y)的
{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
3分之2(X-Y)-4分之X+Y=-1,6(X+Y)-4(2X-Y)=16
解方程组:2(x-y)/3-x+y/4=-1 ,6(x+y)-4(2x-y)=16
4x-(2x+y+16)/2=-6y 2x+3y=7-x-2y