Register Now

Login

Lost Password

Lost your password? Please enter your email address. You will receive a link and will create a new password via email.

222-9+11+12:2*14+14 = ? ( )

Toán Lớp 8: Tìm `x` nguyên để: `-1/(x+2) in ZZ`

Toán Lớp 8: Tìm x nguyên để: -1/(x+2) in ZZ

Comments ( 2 )

  1. Để 1/( x + 2 ) ∈ Z thì 1 vdots x + 2 
    ⇒ x + 2 ∈ Ư( 1 )
    Mà x ∈ Z ⇒ x + 2 ∈ { 1 ; – 1 }
    ⇒ x ∈ { – 1 ; – 3 }
    Vậy , x ∈ { – 1 ; – 3 } thì – 1/( x + 2 ) ∈ Z .

  2. -(1)/(x+2)
    Để ptrình nguyên thì 1\vdotsx+2
    ->x+2∈Ư(1)
    ->x+2∈{±1}
    ->x∈{1-2;-1-2}
    ->x∈{-1;-3}
    Vậy x∈{-1;-3} thì -(1)/(x+2)∈Z

Leave a reply

222-9+11+12:2*14+14 = ? ( )