圆x^2+y^2+2y=9与(x-3)^2+(y+4)^2=16的位置关系是A外离B 外切C 相交D 内切

若／X+Y-9／+（2X-Y+3)=0求X与Y的值 x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 3(x+y)-2(x-y)=11 4(x+y)+3(x-y)=9 4(x-y)-3(x-y)=9 5(x-y)+2(x-y)=11 x(y+2)+(4-x)=9与x(y+3)+y(8-x)=14解方程式 (3x+2y)+(5x-y)i=17-2i.求x与y ：已知x与y互为相反数,且2x-y=3,则x-y= 已知方程组{2x+y=6 x+2y=9},求x+y与x-y的值 (x-y) (x-2y)+(x+2y) (x-3y)-2(x-3y) (x-4y)= (x+y)(x-y)+(x-y)平方-(x-y)(3x-y) 其中x=-2 y=3分之一 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) (x+y)(2x-3y)=?   如果x=5分之2y,x与y【 】比例；如果x乘y=9分之4,x与y【 】比例；如果x-y=2  如果x=5分之2y,x与y【 】比例；如果x乘y=9分之4,x与y【 】比例；如果x-y=20,x与y【 】比例. 已知圆x^2+y^2+x-6y+m=0与直线x+2y-3 |2x-y+5|与|3x-2y-2000|互为相反数,则9x-5y=?RT 【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2= 已知x-y=3,求[（x+y)(x-y)-(x-y)^2+2y(x-y)]除以的值 通分:x-y/2x+2y与xy/(x+y)^2 ,2mn/4m^2-9与2m-3/2m+3格式：例如：x-y/2x+2y与xy/(x+y)^2最简公分母是.x-y/2x+2y=.xy/（x+y）^2=.