解方程组{x+y=500,(50%x+40%y)×0,9=157
解方程组{x+y=500,(50%x+40%y)×0,9=157
解方程组x+y=500 【(1+50%)x+(1+40%)y】×90%=500+157
解方程组(x+y)(x-2y)=-5 (x-y)(x+2y)=7
解方程组 x^2+2xy+y^2=9,(x-y)^2-4(x-y)+3=0
解方程组:2/(x+y)+5/(x-y)=18 9/(x+y)-10/(y-x)=66
解方程组:2/(x+y)+5/(x-y)=18 9/(x+y)-10/(y-x)=66
解方程组 2x+y(y-2x)=9 (x+y)(x+y-3)=10
解方程组{4/x+y+6/x-y=3, 9/x-y-1/x+y=1
解方程组:{4/x+y+6/x-y=3 9/x-y-1/x+y=1}
解方程组x^2-y^2=x+y 4x^2-y^2+2x-y=0过程
解方程组{x+3=5y 3x+2y+9=0}
解方程组①x+3y=7②x²-9y²=-35 解方程组①x²-xy-2y²=0②