3x+4y=15 3x+6y+3=0

已知x,y满足x²+y²-4x+6y+13=0则(3x+y)²-(3x+y)(3x-y)的 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 已知x,y满足:x平方+y平方-4x+6y+13=0求(3x+y)-3（3x-y)(x+y)-(x-3y)(x+3y)= 解方程组 10（x-y)=3(x+y)+15 6(x+y)=4(2x-y)+16 已知x*x+y*y-4x-6y+13=0,求3x+4y的值 x平方+y平方-4x-6y+13=0 ,求3x+4y 【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2= 若2x-3y+4=0则x（x*x-1)+x(5-x*x)-6y+7