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 7: tìm x biết (2/3x-1/5)(3/5x+2/3)<0

Toán Lớp 7: tìm x biết (2/3x-1/5)(3/5x+2/3)<0

Comments ( 2 )

  1. Giải đáp:
     
    Lời giải và giải thích chi tiết:
     (2/3x – 1/5)
    \text{=>Vậy ta có} (2/3x – 1/5)<0 hoặc ( 3/5x + 2/3)<0
    TH1: 2/3 . x – 1/5 < 0
    <=> 2/3 . x < 1/5
    <=> x < 1/5 : 2/3
    <=> x < 3/10
    TH2:  3/5x + 2/3<0
    <=> 3/5 . x  < -2/3
    <=> x < -2/3 : 3/5
    <=> x < -10/9
    \text{=> x ∈ {3/10 ; -10/9}}

  2. ( 2/3x – 1/5 )( 3/5x + 2/3 ) < 0
    – Vậy: ( 2/3x – 1/5 ) < 0 hoặc ( 3/5x + 2/3 ) < 0
    – TH1: 2/3x – 1/5 < 0
    2/3x < 1/5
    x < 1/5 : 2/3
    x < 3/10
    – TH2: 3/5x + 2/3 < 0
    3/5x < (-2)/3
    x < (-2)/3 : 3/5
    x < -10/9
    => x ∈ { 3/10 ; -10/9 }
    @Rin

Leave a reply

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