x-y=178.17求x与y

x-y=178.17求x与y y/x=(x-y)/y 试求y与x之间的函数关系式 5x-6y= -28 ,3x+4y=6求x与y x+y=33,x*3+y*4=100,求x与y的值 (3x+2y)+(5x-y)i=17-2i.求x与y 已知方程4x-y=10中,x与y互为相反数,求x,y. x²+y²+1.25=2x+y 求X与Y 若／X+Y-9／+（2X-Y+3)=0求X与Y的值 [跪求]x+y+(x-y)=360,X与Y的解分别是多少?T_T 已知方程组{2x+y=6 x+2y=9},求x+y与x-y的值 已知(x+y)(x+y)=25,(x-y)(x-y)=9求xy与xx+yy的值 函数f(x,y)=xy/x*2 y*2,求limf(x,y)与limf(x,y) 二元函数f(x,y)=x+y/x-y,求f(y/x,x/y) 已知:3x-5y=0,求x/y,x-y/y,x-y/x 求y'=y/(y-x) |x-y+3|与|x+y-1999|互为相反数,求x+y/x-y的值 x^y=y^x,求dy. x+y+|x-y|=-56 求x*y 最小值