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: 1> 1/3 + 2/3 : x = -7 2> ( 2x + 3/5 ) ^ 2 – 9/25 = 0

Toán Lớp 7: 1> 1/3 + 2/3 : x = -7
2> ( 2x + 3/5 ) ^ 2 – 9/25 = 0

Comments ( 2 )

  1. Giải đáp:
    1) x=-1/11
    2) x=0 hoặc x=-3/5
    Lời giải và giải thích chi tiết:
    1) 1/3 + 2/3 : x = -7
    <=> 2/3 : x = -7-1/3
    <=> 2/3 : x = -22/3
    <=> x = 2/3 : (-22)/3
    <=> x = -1/11
    Vậy x=-1/11
    2) (2x + 3/5)^2 – 9/25 = 0
    <=> 2x + 3/5)^2 = 9/25
    TH_1: (2x + 3/5)^2 = (3/5)^2
    <=> 2x + 3/5 = 3/5
    <=> 2x = 3/5 – 3/5
    <=> 2x=0
    <=> x=0
    TH_2: (2x + 3/5)^2 = (-3/5)^2
    <=> 2x + 3/5 = -3/5
    <=> 2x=-3/5-3/5
    <=> 2x=-6/5
    <=> x=-3/5
    Vậy x=0 hoặc x=-3/5

  2. 1) 1/3 + 2/3 : x = -7
        2/3 : x = -7 – 1/3
        2/3 : x = -22/3
        x = 2/3 : -22/3
        x = -1/11
    2) (2x + 3/5)^2 – 9/25 = 0
        (2x + 3/5)^2 = 0 + 9/25
        (2x + 3/5)^2 = 9/25
        (2x + 3/5)^2 = (±3/5)^2
    => 2x + 3/5 in {3/5; -3/5}
    => 2x in {0; -6/5}
    => x in {0; -3/5}
    Vậy x in {0; -3/5}

Leave a reply

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