X+Y=7 ：10X+Y+45=10Y+X怎么解

X+Y=7(100X+Y)-(10Y+X)=(10Y+X)-(10X+Y) X+Y=7 ：10X+Y+45=10Y+X怎么解 x+y=20,x-y=10,y= 例X=1 y=21.X+Y=5 X-Y=15 2.2X+3Y=4 5X+6Y=7 3.X+3Y=5 3X+Y=-1 4.2X+Y=3 3X+5Y=11 5.4X+3Y=6 2X+Y=4 6.X+Y=180 X=3Y-10 7.3X-2Y=3 2X-Y=7 8.5X+3Y=7Y X+Y=45 9.3X+4Y=126X+8Y=24 X:6Y=1:4 10.X+Y=138 X-45=Y+53 11.X+Y=60 14Y=20X 12.2X+3Y=15.5 5X+6Y=35 13.X+Y=170 3 y+10x=x+y+9 10y+x=y+10x+27 (x+y)/6+(x-y)/10=1,(x+y)/6-(x-y)/10=5 {6/x+y+10/x-y=30 6/x+y-10/x-y=-1 y+y+x=10,x+y+x=8,y=?,x=? x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 已知|x|+x+y=10 |y|+x-y=12 求 x+y=? 已知|x|+x+y=10,|y|+x-y=12,求x+y的值 已知|x|+x+y=10,x+|y|-y=12,求x、y的值 已知/x/+x+y=10,/y/+x-y=12.求x+y的值 (x+y)(x+y-10)+25=0,且x-y=3,求x,y (x+y)(x+y-10)+25=0,且x-y=3,求x,y X+Y-8X+10Y+41=O,求X/Y-Y/X的值 x,y 满足x(x-2)-y(y-6)=-10,求x,y的值 求f(x,y)=x+y+7的最大值,使(x,y)满足x+2y≤10,2x+y≥6,y≥0