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: Bài 1: a) 3×3 + 6×2 + 3x d) x3 – 4×2 – 8x + 8 b) – 16 x2 + 8xy – y2 + 49 e) x4 – 5×2 + 4 c) 6xy + 12x – 4y – 8

Toán Lớp 8: Bài 1:
a) 3×3 + 6×2 + 3x d) x3 – 4×2 – 8x + 8
b) – 16 x2 + 8xy – y2 + 49 e) x4 – 5×2 + 4
c) 6xy + 12x – 4y – 8

Comments ( 2 )

  1. Giải đáp:
     
    Lời giải và giải thích chi tiết:
    $\ a) 3x³ + 6x² + 3x $
    $\ = 3x(x² + 2x + 1) $
    $\ = 3x(x + 1)² $
    $\ b) – 16x² + 8xy – y² +  49 $
    $\ = – [(16x² – 8xy + y²) – 49 ] $
    $\ = – [(4x – y)² – 7²] $
    $\ = – (4x – y – 7)(4x – y + 7) $
    $\ c) 6xy + 12x – 4y – 8 $
    $\ = (6xy + 12x) – (4y + 8) $
    $\ = 6x(x + 2) – 4(y + 2) $
    $\ = (x + 2)(6x – 4) $
    $\ = 2(x + 2)(3x – 2) $
    $\ d) x³ – 4x² – 8x + 8 $
    $\ = (x³ + 8) – (4x² + 8x) $
    $\ = (x + 2)(x² – 2x + 4) – 4x(x + 2) $
    $\ = (x + 2)(x² – 2x + 4 – 4x) $
    $\ = (x + 2)(x² – 6x + 4) $
    $\ e) x^{4} – 5x² + 4 $
    $\ = x^{4} – 4x² – x² + 4 $
    $\ = (x^{4} – 4x² + 4) – x² $
    $\ = (x² – 2)² – x² $
    $\ = (x² – x – 2)(x² + x – 2) $

Leave a reply

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