Question

a) 3n + 4 \(⋮\) 2n - 1

b) 3n + 5 \(⋮\) 4 - n

c) 3n + 8 \(⋮\) 5 - 2n

Answer 1

\(a,3n+4⋮2n-1\Rightarrow6n+8⋮2n-1\left(1\right)\)

\(2n-1⋮2n-1\Rightarrow6n-3⋮2n-1\left(2\right)\)

\(\text{Từ}\left(1\right)\text{ và }\left(2\right)\Rightarrow\left(6n+8\right)-\left(6n-3\right)⋮2n-1\)

\(\Rightarrow6n+8-6n+3⋮2n-1\)

\(\Rightarrow11⋮2n-1\)

\(\Rightarrow2n-1\inƯ\left(11\right)=\left\{-11;11;1;-1\right\}\)

\(\Rightarrow\text{Ta có bảng sau: }\)

2n-1	-11	11	1	-1
n	-5	6	1	0
Đánh giá	Chọn	Chọn	Chọn	Chọn

\(\text{Vậy }n\in\left\{-5;6;1;0\right\}\)