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 biết a, 4( 18 – 5x ) – 12( 3x – 7 ) = 15( 2x – 16 ) – 6( x + 14 ) b, 2( 5x – 8 ) – 3( 4x – 5 ) = 4( 3x – 4 ) + 11.

Toán Lớp 8: Tìm x biết
a, 4( 18 – 5x ) – 12( 3x – 7 ) = 15( 2x – 16 ) – 6( x + 14 )
b, 2( 5x – 8 ) – 3( 4x – 5 ) = 4( 3x – 4 ) + 11.

Comments ( 2 )

  1. Giải đáp+ Lời giải và giải thích chi tiết:
    a, 4( 18 – 5x ) – 12( 3x – 7 ) = 15( 2x – 16 ) – 6( x + 14 )
    ⇔ 72 – 20x – ( 36x – 84) = 30x – 240 – ( 6x + 84)
    ⇔ 72 – 20x – 36x + 84 = 390x – 240 – 6x – 84
    ⇔ – 20x – 36x – 30x + 6x = -240 – 84 – 72 – 84
    ⇔ -80x = – 480
    ⇔  x = 6
    b, 2( 5x – 8 ) – 3( 4x – 5 ) = 4( 3x – 4 ) + 11.
    ⇔ 10x – 16 – ( 12x – 15) = 12x – 16 + 11
    ⇔ 10x – 16 – 12x + 15 = 12x – 16 + 11
    ⇔ 10x – 12x – 12x = -16 + 11 + 16 -15
    ⇔  – 14x = – 4
    ⇔ x = $\frac{2}{7}$ 
     

  2. Giải đáp + Lời giải và giải thích chi tiết:
     a) 4 (18-5x) – 12 (3x-7) = 15 (2x-16) – 6 (x+14)
    ⇔ 72 – 20x – 36x + 84 = 30x – 240 – 6x – 84
    ⇔ 156 – 56x = 24x – 324
    ⇔ -56x – 24x = -156 – 324
    ⇔ -80x = -480
    ⇔ x = 6
    Vậy x = 6
    b) 2 (5x-8) – 3 (4x-5) = 4 (3x-4) + 11
    ⇔ 10x – 16 – 12x + 15 = 12x – 16 + 11
    ⇔ -2x – 1 = 12x – 5
    ⇔ -2x – 12x = 1 – 5
    ⇔ -14x = -4
    ⇔ x = 4/14
    ⇔ x = 2/7
    Vậy x = 2/7

Leave a reply

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

About Ayla