若多项式x的二次方-3xy+ay的二次方分解为(x-5y)(x-by)则a.b的值为

若多项式x的二次方-3xy+ay的二次方分解为(x-5y)(x-by)则a.b的值为
若多项式x的二次方-3xy+ay的二次方分解为(x-5y)(x-by)则a.b的值为

若多项式x的二次方-3xy+ay的二次方分解为(x-5y)(x-by)则a.b的值为
(x-5y)(x-by)化简得x^2-bxy-5xy+5by^2,则-bxy-5xy=-3xy,即b=-2所以5b=a,即a=-10

(x-5y)(x-by)=x^2-(5+b)xy+5by^2
对应原多项式有5+b=3, a=5b 得a=-10, b=-2

a等于-10
b等于-2