化简0.1(10-X)+0.5(10-Y)+(10-15+X+Y）=9

化简0.1(10-X)+0.5(10-Y)+(10-15+X+Y）=9 解方程组：（0.2x+0.1y）/2- （4x-y）/10=（x-y）/5+ (3x+0.5y)/30 (3x+2y-1)/8=3-(0.8x-5y)/41=-= 化简(x+y)-(2x+y/2)-(3x+y/6)-(4x+y/12)-(5x+y/20)-……-(10x+y/90) x y是两个变量,而且x=4/y.请先填表,再判断x和y是什么比例x 0.1 0.2 ( ) 0.5y 40 ( ) 10 8 （10x+y）-（10y+x）化简 化简：3（x+y）+5=10y+x 化简 1/7（-2x+3y)(-2x-3y)-10(x+y)的平方 (x+y)²-10(x+y)+25 答完追10分.公式法证明题x>=o,y>=0.证明.(x+y)^2/2+(x+y)/4>=(x*y^0.5)+(y*x^0.5) 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 25(x-y)*2+10(y-x)+125（x-y)^2+10(y-x)+1 [2X+(Y-10)][2X-(Y-10)]-(3X+Y)(3X-Y) x+y=20,x-y=10,y= (x+5y)^+(2x+10y)(3x-y)+(3x-y)^ (x+5y)²-(2x+10y)(3x-y)+(3x-y)² 已知|x|+x+y=10,|y|+x-y=12,求x+y的值