A) (X4 + 8X2 + 16)

Bài 11: câu nào sai:

a)

(x

4

+ 8x

2

+ 16) : (x

2

+ 4) = x

2

+ 4

b)

(25 - x

2

) : (x+5) = 5 - x

c)

( x

3

+1) : (x

2

- x+1) = x - 1

d)

9(x - 2y)

10

: (3x –-6y) = 3(x - 2y)

9