化简:5*a‘2/5ab= ,9a*b'2+6abc/3*a'2*b= ,(x+y)y/x*y'2=

define A(x,y) x*y-x/y main(){int a=5,b=2,y;y=A(a+b,a-b);prin x²（x+y)(y-x)-xy(x+y)(x-y) 已知a+b=4,ab=-2,求多项式3a²b+3 已知集合A=｛(x,y)|3x-7y=-5},B={(x,y)|2x+9y=40},求A∩B（用列举 几道因式分解..4ab(a+b)^2-6a^2b(a+b)(x+y)^2(x-y)+(x+y)(x-y)^22a(a-3 ab-a*1/3b=?3x*5x-3x*2y=? 有理数ab定义:a*b=3a+2b.则[（x+y)*(x-y)]*3x.怎么化简? ab是有理数a*b=2a-3b求【（x-y)*（x+y)】*x的值 已知：A=X*X-3xy+y*y,B=2x*x+xy-3y*3y.求A+B,A-B,A+2B 已知A=2x-y,B=x+y,计算A^2-2AB 先化简,再求值:(3x-y)^2-5x(x-y),其中x=0.2,y=0.1 , (2a+b)(2a-b)-3(2a-b 3a-3b/10ab*25a^b3/a^-b^= x^-4y^/x^+2xy+y^/x+2y/2x^+2xy 已知A=2x+y,B=2x-y,计算AB-B的平方