Question

(2x+11)⋮(x+5) dạng bài mới khó quá

⋮(dấu hiêu chia hết)

Answer 1

(2\(x\) + 11) ⋮ (\(x+5\)) (đk \(x\) ≠ - 5)

2\(x\) + 10 + 1 ⋮ \(x+5\)

2.(\(x+5\))  + 1 ⋮ \(x+5\)

                   1 ⋮ \(x+5\)

\(x+5\) \(\in\) Ư(1) = {-1; 1}

\(x\)  \(\in\) {-6; - 4}

Vậy \(x\) \(\in\) {-6; -4} 

Answer 2

\(\left(2x+11\right)⋮\left(x+5\right)\)

\(\Rightarrow\left(2x+10+1\right)⋮\left(x+5\right)\)

\(\Rightarrow\left[2\left(x+5\right)+1\right]⋮\left(x+5\right)\)

\(\Rightarrow1⋮\left(x+5\right)\)

\(\Rightarrow x+5\inƯ\left(1\right)=\left\{-1;1\right\}\)

\(\Rightarrow x\in\left\{-6;-4\right\}\)