a=3x^2-2y^2,b=x^2+y^2,c=2xy+x^2 那么x=-1 y=2时.a-[2b-[3a-c]的值

x+y=a,x-y=b.求2x-3y等于 A={(x,y)|y=-x^2+mx-1},B={(x,y)|y=3-x,0A={(x,y)|y=-x^2+mx-1},B={(x,y)|y=3-x,0 若集合A={(x,y)|y>=|x-2|} ,B={(x,y)|y A={（x,y)|y>=0.5|x-2|},B={(x,y)|y 初一因式分解练习题,谁好心帮我解下表示平方1.2X~-3XY-X2.(X+Y)~(X+Y)(X-Y)(X+Y)(Y+Z)3.3X(a+2b)~-6XY(a+2b)4.a(x-y)-b(X-Y)-C(Y-X)5.(b-a)~-2a+2b6.(x-y)~-m(y-x)+y-x7.x(x-y)(a-b)-y(y-x)(b-a)8.已知a+b=13,ab=40,求 b+ab~的值 已知3x+2y=a,2x+3y=b,则(x+y)(x-y)=? 集合A={（x,y)|y=-x^2+mx-1},B={(x,y)|y=3-x,0 方程组:3（x+y)-a(x-y)=16,2(x+y)+b(x-y)=15的解是什么? 1、(-y^3)^5/y^3/ y^2+2(-y)^102、(x-y)^7/(y-x)^6+(x+y)^3/(x+y)^23、已知X^a=5,x^b=3,求X^(3a-2b)的值 已知：A=X*X-3xy+y*y,B=2x*x+xy-3y*3y.求A+B,A-B,A+2B 如果A={（x,y）|x,y+2>0},B={（x,y）|2x+3y-6>0},C={（x,y）|x-4 (2x+y)(2x-3y)+x(2y+y) 2a(x-y)-4b(x-y) A={(X,Y)|X+Y>=1},B={(X,y)|X^2+y^2=1},B={(X,y)|X^2+y^2 通分 a/(y-x)^2,b/(x-y)(x+y) 因式分解a(x-y)+b(y-x)+(2x-y) 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 x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 集合A={(x,y)|x-2y=1}B={(x,y)|x+3y=6},则A∩B= A∪B=?