Question

(x-y)7÷(x-y)6计算

Answer 1

(x+y) =x +2xy+y =7 (x-y) =x -2xy+y =3 两式相加, x +y =5 两式相减, xy=1 x^6+y^6 =(x ) +(y ) =(x +y )(x^4-x y +y^4) =5[(x +y ) -3xy] =5×(25-3) =110

Answer 2

当X=Y,为0.当X不等于Y为x-y

Answer 3

(x-y)^7(y-x)^6
=(x-y)^7(x-y)^6
=（x-y)^(7+6)
=(x-y)^13