{X+0.2Y-4.94=15{0.02Y=10×0.4%X

{X+0.2Y-4.94=15{0.02Y=10×0.4%X x=15y 2（x+y)-3(x-y)=3 ,4(x+y)+3(x-y)=15 x^2+y^2=15,x+y=7,x＞y,求x-y x+x+x=15,x+y+y=19,求y-x等于几 x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 已知x+y+y=20,x+y=15求x.y 化简 x / y(x+y) - y / x(x+y) = (12-x)*y+x*2=26 (15-x)*y+y*2=35(12-x)*y+x*2=26 (15-x)*y+y*2=35 x(x+y)(x-y)-y(y+x)(y-x)=(x-y)( )填空 x+y=15 0.2x+0.5y=4.5 怎么解 xy=15,x+y=8,x,y=? x+8y=15 4x+y=29 x+y=15 1.15x+1.1y=17 {2x+y=15 x+2y=18 x+y+4.5=12.82x+1.5y=15 x-3y=2x+y-15=1 x+4y=14 x+5y=15