Question

Tìm số tự nhiên n sao cho 4n-6 chia hết cho 2n-1

Answer 1

Ta co:4n-6⋮2n-1 =>4n-2-4⋮2n-1 =>2(2n-1)-4⋮2n-1 Vi 2(2n-1)⋮2n-1 nen: 4⋮2n-1 =>2n-1∈B(4) =>2n-1∈{1;2;4} Ta co bang sau:

2n-1	1	2	4
n	1	1,5(loai)	2,5(loai)

Vay n=1