圆C:x^2+y^2-6x+12y+20=0,直线L：2mx-y-8m-3=0(m属于实数)m为何值时,直线L被圆C截得的弦长最短?并求出这个最小值

【2(x-y)(x-y)(x-y)-8(x-y)(x-y)(x+y)+6y(x-y)(x-y)]/2(x-y)(x-y) 化简(x+y)-(2x+y/2)-(3x+y/6)-(4x+y/12)-(5x+y/20)-……-(10x+y/90) a(x-y)(x+y)-b(y-x)(x+y)-c(x-y)^2(y+x)提取公因式 [12(x+y)^3+3(x+y)(x-y)^2]÷6(x+y) x+y/2+x-y/3=6,4(x+y)-3(x-y)=-20 {(x+y)/2+(x-y)/3=6 4(x+y)-3(x-y)=-20 4(x+y)-3(x-y)=-20,2/x+y+3/x-y=6 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 谁能帮我因式分解啊.A.4（x-y+1)+y(y-2x) B.5+7x-6x² C.12x²+xy-6y² 3/X+2/Y=6/1等介于?（X不等于18）A.x/3+y/2=1/6 B .3Y+2X C.X=18Y/Y-12 D .Y=12X/X-18 x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 如果A={（x,y）|x,y+2>0},B={（x,y）|2x+3y-6>0},C={（x,y）|x-4 计算:(x-y)^2*(y-x)^2*(x-y)^6 6(x+y)2-2(x-y)(x+y)因式分解 化简y(x+y)+(x+y)(x-y)-x^2 化简求值:(x+y)-(2x+1/2y)-(3x+1/6y)-(4x+1/12y)-(5x+1/20y)-.(10x+1/90y) ,其中x=1,y=-2 (x-y)^2+12(x-y)+36 9(x-y)-12(y-x)^2