已知A=(2x-y)B=(-2x-y),求A*B

已知x+y=a,x-y=b.求:x^2+y^2;xy 已知3x+2y=a,2x+3y=b,则(x+y)(x-y)=? 已知a,b,X,Y属于R+,求证a^2/X+b^2/Y>=(a+b)^2/(X+Y) 已知：A=X*X-3xy+y*y,B=2x*x+xy-3y*3y.求A+B,A-B,A+2B 已知实数a,b,x,y,满足不等式（a+b）(x+y)>2(ay+bx),求证（x-y）/(a-b)+(a-b)/(x-y)>=2 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 已知集合A={x,y|x^2+y^2=1},B={(x,y)|kx-y 已知集合A={(x,y)|x+y=1},B={(x,y)|kx-y-2 已知集合A={x+y|y=x^2,x属于R},B={y|y=1-|x|,x属于B},求A∩B. 几道比例线段题目已知两实数a,b满足a^2-4ab+4b^=0,求(a+b)/a已知x/2=y/3,求(x-y)/y ,(x+y)/y ,(x+y)/(x-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x+y=a,2x-y=-2a,求[（x/y-y/x)/(x+y)-x(1/x-1/y)]/[(x+1)/y]的值 已知A=2x+y,B=2x-y,计算A^2-B^2 已知A=2x+y,B=2x-y,计算A^2-B^2 已知A=2x+y,B=2x-y,计算A平方-B平方 已知A=2x+y,B=2x-y,计算A²-B². 已知A=2x+y,B=2x-y计算A²-B² 已知A=(2x-y)B=(-2x-y),求A*B