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 này với ạ d, 4.(x – 1).(x + 5)-(x – 2).(x + 5) = 3.(x – 1).(x + 2) e, (8 – 5x).(x + 2) + 4. (x – 2) . (x + 1) + 2.($x^{2}$ –

Home/ Toán Lớp 8: =))) bài này với ạ d, 4.(x – 1).(x + 5)-(x – 2).(x + 5) = 3.(x – 1).(x + 2) e, (8 – 5x).(x + 2) + 4. (x – 2) . (x + 1) + 2.($x^{2}$ –

Toán Lớp 8: =))) bài này với ạ d, 4.(x – 1).(x + 5)-(x – 2).(x + 5) = 3.(x – 1).(x + 2) e, (8 – 5x).(x + 2) + 4. (x – 2) . (x + 1) + 2.($x^{2}$ –

Tháng Chín 19, 2022 Toán học 2 Comments 0 views

Toán Lớp 8: =))) bài này với ạ
d, 4.(x – 1).(x + 5)-(x – 2).(x + 5) = 3.(x – 1).(x + 2)
e, (8 – 5x).(x + 2) + 4. (x – 2) . (x + 1) + 2.($x^{2}$ – 4) = 0

Comments ( 2 )

  1. maitrucloan
    maitrucloan
    19 Tháng Chín, 2022 at 1:21 chiều
    Reply
    d, 4.(x – 1).(x + 5)-(x – 2).(x + 5) = 3.(x – 1).(x + 2)
    ⇔ 4. (x²+ 5x – x- 5)- x²+ 5x- 2x- 10= 3. (x²+ 2x- x- 2)
    ⇔ 4x²+ 16x – 20- x²+ 3x= 3x²+ 3x- 6
    ⇔ 3x²+ 19x- 20= 3x²+ 3x- 6
    ⇔  16x=26
    ⇔ x= $\frac{13}{8}$  
    e, (8 – 5x).(x + 2) + 4. (x – 2) . (x + 1) + 2.(x² – 4) = 0
    $\Longleftrightarrow$ $\textit{8x+ 16- 5x²+ 10x+ 4. (x²+ x- 2x- 2)- 2x²- 8= 0 )}$
    $\Longleftrightarrow$ $\textit{18x+ 16- 5x²+ 4x²+ 4x- 8x- 8- 2x²- 8= 0 )}$
    $\Longleftrightarrow$ $\textit{14x- 3x²= 0 )}$
    $\Longleftrightarrow$ $\textit{x.(14- 3x)= 0 )}$
    $\Longleftrightarrow$ \(\left[ \begin{array}{l}x=0\\14- 3x=0\end{array} \right.\) 
    $\Longleftrightarrow$ \(\left[ \begin{array}{l}x=2\\x=\dfrac{14}{3}\end{array} \right.\) 

  2. doanthulan
    doanthulan
    19 Tháng Chín, 2022 at 1:21 chiều
    Reply
    d, 4.(x – 1).(x + 5)-(x – 2).(x + 5) = 3.(x – 1).(x + 2)
    ⇔ 4. (x²+ 5x – x- 5)- x²+ 5x- 2x- 10= 3. (x²+ 2x- x- 2)
    ⇔ 4x²+ 16x – 20- x²+ 3x= 3x²+ 3x- 6
    ⇔ 3x²+ 19x- 20= 3x²+ 3x- 6
    ⇔  16x=26
    ⇔ x= $\frac{13}{8}$ 
     

Leave a reply

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

Bích Hải

About Bích Hải