12x+24y=60 16*0.8x+27*0.8y=60 化简求值

(12-2x)/X=(-16-2Y)/Y X^2+Y^2=25 Y x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 先化简再求值; 解方程组 x(x-y)-y(x+y)+2xy 其中x=2 ,y=-22.x[x-x(x-1)],其中x=-2解方程组4x+3y=12x-y=32.y+1=2x 4x-y=2 3.2x+2y=0 2x-y+24=0 8（x-y)=3（x+y)-12 6（x+y)=4（2x-y)+16 8（x-y)=3（x+y)-12 6（x+y)=4（2x-y)+16 （1）y=9/7x²-7/8x+9/5（2）y=2/3x²+2/3x-1（3）y=4/5x²-7/3x+1（4）y=3/4x²-3/2x-2（5）y=-x²+5/2x-6（6）y=-3x²+9x-5（7）y=4x²+16x-24（8）y=-2x²-8x+16（9）y=5x²-12x+10（10）y=-x²-7x+8 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 (X,Y) f(x,y)={12y^2,0 12y(x-y)^2-8(x-y)^3=? 12x+24y=60 16*0.8x+27*0.8y=60 化简求值 3x+y=2 -y/x+y=123x+y=2 （-y/x）+y=12 x/24+y/18=11/12 x/8+y/16=3/2, 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 解一些方程组8(1/x+1/y)=16/x+x/y=19/(x+y)+6/(x-y)=312(x+y)=12(x-y)-11/(2x+y)-1/(x-2y)=53/(2x+y)-2/(x-2y)=5过程可以省略. 因式分解30题(要过程)am+an+bm+bn x^2+5y-xy-5x x2+xy+2xz+x (a+b)x-(b+a)y -12x(x-y)-(y-x)x^2 2x^2+4x+2 x(x+z)-y(y+z) 2(x^2-3ab)+x(4a-3b) 4x^2+12xy+9y^2-25 x^4-16 16x^4-1 x^2+9x+8 x^2-10xy+24y^2 2x^2+15xy-8y^2 3x^2-6xy+3y^2 24x^2+22x-21 -x^2+4xy- x+x=() x*x=() x-0.8x=() 1.2*2y=()