A=x^2+3xy-y^2,B=-2x^2+xy-y^2.当x

已知a=x^+xy+y^ b=-3xy-x^求2A-3B 已知：A=X*X-3xy+y*y,B=2x*x+xy-3y*3y.求A+B,A-B,A+2B 因式分解（x+y-2xy)(x+y-2)+(xy-1)^2设x+y=a,xy=b, 已知A=X-2y+2xy,B=3x-6y+4xy 求3A-B A=x^2+3xy-y^2,B=-2x^2+xy-y^2.当x 已知A=8x^2y-6xy^2-3xy,B=7xy^2-2xy+5x^2y求A-B 两个数学计算.a/b-(a-b)/b=x^2+xy/（x-y）÷xy/（x-y） 已知x+y=a,x-y=b.求:x^2+y^2;xy 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. A=x²+xy+y²；B=-3xy-x²,求2A-3B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=5x^2-3xy^2+4xy,b=3xy^2-2xy+x^2y,则a-b=【】 已知x+y=a,xy=b,求x+y^2,x^2-xy+y^2 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) 3a-3b/10ab*25a^b3/a^-b^= x^-4y^/x^+2xy+y^/x+2y/2x^+2xy(3a-3b)/(10ab)*(25a^b3)/(a^-b^)= (x^-4y^)/(x^+2xy+y^)/(x+2y)/(2x^+2xy)=