24/x+24/y=120/x+20/y+20/y=1

24/x+24/y=120/x+20/y+20/y=1 X+X+X+X+Y+Y+Y=36,X+X+Y+Y+Y=24,那么X=【】,Y等于【】.【】 x+y/2+ x-y/2=6 2(x+y)-3x+3y=24 求X Y 已知2/x+2/y=根号24,求 x/y(x-y) - y/x(x-y)的值 已知2/x 2/y=根号24,求 x/y(x-y) - y/x(x-y)的值 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=(100-20x)/4+x 4(16x/24+x)+20(y-x-16x/24)=100 若x+y=3 x²-y² 则x-y=?若x+y=3 x²-y²=24 则x-y=? x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 几道 数学题急啊 对了再加20分(x+y)^2-(x+y)^3(x-y)^2-(x-y)^3 (x-y)^2-(y-x)^32(x-y)-3(y-x)^24ab(a+b)^2-6a^2b(a+b)(x+y)(x-y)-(x+y)^28a(x-y)^2-4b(y-x)a=-5 a+b+c=-5.2求代数式a^2(-b-c)-3.2a(c+b)的值 化简 x / y(x+y) - y / x(x+y) = 概率密度f(x,y)=24y(1-x-y),求P{X0,y>0,x+y x+y=24 2x+4y=72 X=3Y Y=X-24 3x-7y=-24 x+y=12 x+y=45,24x+18y=960 18x+6y=24 x=y 解方程组（三分之x+y）+y=6,3(x+y)-y=24