Question

(4x+7) chia hết cho (2x+1)

 

Answer 1

4x+7 chia hết cho 2x+1

=>4x+2+5\(⋮\)2x+1

=>\(5⋮2x+1\)

=>\(2x+1\in\left\{1;-1;5;-5\right\}\)

=>\(x\in\left\{0;-1;2;-3\right\}\)

Answer 2

Ta có:

4x + 7 = 4x + 2 + 5 = 2(2x + 1) + 5

Để (4x + 7) ⋮ (2x + 1) thì 5 ⋮ (2x + 1)

⇒ 2x + 1 ∈ Ư(5) = {-5; -1; 1; 5}

⇒ 2x ∈ {-6; -2; 0; 4}

⇒ n ∈ {-3; -1; 0; 2}