M + ( 5X2 – 2XY ) = 6X2+ 9XY – Y2B

Bài 27:Tìm đa tức M , biết:

a.M + ( 5x

2

– 2xy ) = 6x

2

+ 9xy – y

2

b.M – (3xy – 4y

2

) = x

2

-7xy + 8y

2

c.(25x

2

y – 13 xy

2

+ y

3

) – M = 11x

2

y – 2y

2

;

d.M + ( 12x

4

– 15x

2

y + 2xy

2

+7 ) = 0