CÂU 115.2 3U U − U − N N1 2N N NA) UN+3 =2UN+2+3UN+1 B) UN+3 =2UN+2+...

Câu 115.2 3u u

u

n N

1

2

n

n

n

A) u

n

+

3

=2u

n

+

2

+3u

n

+

1

B) u

n

+

3

=2u

n

+

2

+3u

n

C) u

n

+

3

=2u

n

+

2

+3u

n

D)u

n

+

3

=2u

n

+

2

+3u

n

1