Question

tìm x

x+11 là bội của x+2

 

Answer 1

x = 7

( x + 11 ) ⋮  ( x + 2 ) = ( 7 +11) ⋮ ( 7 + 2 ) = 18 ⋮ 9 

Answer 2

\(\left(x+11\right)⋮\left(x+2\right)\Rightarrow\left(x+2\right)+9⋮\left(x+2\right)\)

\(\Rightarrow\left(x+2\right)\inƯ\left(9\right)=\left\{-9;-3;-1;1;3;9\right\}\)

\(\Rightarrow x\in\left\{-11;-5;-3;-1;1;7\right\}\)

Answer 3

\(\Leftrightarrow x+2\in\left\{3;9\right\}\)

hay \(x\in\left\{1;7\right\}\)