-2x^2y+xy+13xy-(-5x^2y)化简-2x^2y+xy+13xy-(-5x^2y) a-(3a+b)+2（a-2b）

((xy+2)(xy-2)-2x²y²+5(xy-y)²)÷(2xy) 化简：3x^2-[5xy-(x^y-3xy)+4x^2y-8xy] x^2-xy/xy-y^2约分 化简(3x^2-5xy)+{-x^2-[-3xy+2(x^2-xy)+y^2]} x^3y(-4y)^2+(-7xy)^2*(-xy)-5xy^3*(-3x)^2 5x^3y*(-3y)^2+(-6xy)^2*(-xy)+xy^3*(-4x^2) （x^2+xy/x-y)/（xy/x-y)计算 2x²y-3(2xy-xy)-xy 因式分解 x-xy+3y-3x 2x+xy-y-4x+5y-6 5x^2y/-1/2xy*3xy^2 2xy+5y^2+( )=x^2+3xy 计算：5xy^2-[3xy^2-(4xy^2-2x^2y)]+2x^2y-xy^2 5xy^2-(3xy^2-(4xy^2-2x^2y))+2x^2y-xy^2求 5xy^2-{2x^y-[3xy^2-（xy^2-2x^2y）]/（-1/2xy）} 5x^2y-3xy^2+4xy-14xy^2+4xy-2x^2y（化简） 已知x^2-xy=5,xy-y^2=-3求3(x^2-xy)-xy+y^2 2x平方y-2xy+3xy平方+5+2xy+x平方y-3xy平方-3 过程! (x^2+2xy+y^2-4xy)*(x^2-2xy+y^2+4xy)