Question

20 chia hết cho 2n + 1

nhớ phân tích giúp mik mai mik di học rồi

ai cho 1 like ok

thanks

Answer 1

để 20\(⋮2n+1\)

=> \(\dfrac{20}{2n+1}\) phải nguyên thì

2n+1\(\inƯ\left(20\right)=\left\{\pm1;\pm2;\pm4;\pm5;\pm10;\pm20\right\}\)

ta có bảng sau

2n+1	-20	-10	-5	-4	-2	-1	1	2	4	5	10	20
2n	-21	-11	-6	-5	-3	-2	0	1	3	4	9	19
n	\(-\dfrac{21}{2}\)	\(-\dfrac{11}{2}\)	-3	-\(\dfrac{5}{2}\)	-\(\dfrac{3}{2}\)	-1	0	\(\dfrac{1}{2}\)	\(\dfrac{3}{2}\)	2	\(\dfrac{9}{2}\)	\(\dfrac{19}{2}\)

vậy .....