已知：A=X*X-3xy+y*y,B=2x*x+xy-3y*3y.求A+B,A-B,A+2B

已知：A=X*X-3xy+y*y,B=2x*x+xy-3y*3y.求A+B,A-B,A+2B 已知a=x^+xy+y^ b=-3xy-x^求2A-3B 已知x+y=a,x-y=b.求:x^2+y^2;xy 已知A=X-2y+2xy,B=3x-6y+4xy 求3A-B 已知x+y=a,xy=b,求x+y^2,x^2-xy+y^2 已知A=8x^2y-6xy^2-3xy,B=7xy^2-2xy+5x^2y求A-B 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6x^2-7xy-3y^2+14x+y+a=(2x-3y+b)(3x+y+10,则a=?,b=? 已知6x^2-7xy-3y^2+14x+y+a=(2x-3y+b)(3x+y+1),则a=?,b=? 已知A=5x²y-3xy²+4xy；B=7xy²-2xy+x²y,且x+y=2,x-y=0,化简求-1/2（A+B)-A. 已知:6x²-7xy-3y²+14x+y+a=(2x-3y+b)(3x+y+1)求a,b的值 已知:6x²-7xy-3y²+14x+y+a=(2x-3y+b)(3x+y+1)求a,b的值 已知A=5x^+2xy-4y^,B=-x^-4xy+y^,C=x^-xy+3y^其中xy满足|2x+1|+(y-4)^=0,就A-2B+C已知A=5x^+2xy-4y^,B=-x^-4xy+y^,C=x^-xy+3y^其中xy满足|2x+1|+（y-4)^=0,求A-2B+C-2B+C的值 已知A=x²+xy+y².,B=x²-xy+y²,x²+3xy+4y²=2,4x²-2xy+y²=3.已知A=x²+xy+y².,B=x²-xy+y²,x²+3xy+4y²=2,4x²-2xy+y²=3。求代数式4A+B-(A-B) 已知A=2x²-5xy+2y²+x-2y,B=x²-5/2xy+y²-2x+y,且A-2B=3a,|x-a|+(y-1)²=0 已知A=x^2+xy+y^2,B=-2xy-x^2,则3A-4B= 已知A=x²+xy+y²,B=-3xy-x²,求2A-3B. 已知A=x²-2xy+y,B=x²+2xy+y²-3,求2A-[B-(B-A)+2A+B] 急.