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 (8x-3).(3x+2)-(4x+7).(x+4)=(2x+1).(5x-1)

Home/ Toán Lớp 8: Tìm X Biết (8x-3).(3x+2)-(4x+7).(x+4)=(2x+1).(5x-1)

Toán Lớp 8: Tìm X Biết (8x-3).(3x+2)-(4x+7).(x+4)=(2x+1).(5x-1)

Tháng Tám 20, 2022 Toán học 2 Comments 0 views

Toán Lớp 8: Tìm X Biết
(8x-3).(3x+2)-(4x+7).(x+4)=(2x+1).(5x-1)

Comments ( 2 )

  1. thienthanh
    thienthanh
    20 Tháng Tám, 2022 at 4:43 chiều
    Reply
    (8x-3)(3x+2)-(4x+7)(x+4)=(2x+1)(5x-1)
    <=>24x^2+16x-9x-6-(4x^2+16x+7x+28)=10x^2-2x+5x-1
    <=>20x^2-16x-34-10x^2+2x-5x+1=0
    <=>10x^2-19x-33=0
    <=>10x^2-30x+11x-33=0
    <=>10x(x-3)+11(x-3)=0
    <=>(x-3)(10x+11)=0
    <=>[(x=3),(x=-11/10):}

  2. hienchaudiem
    hienchaudiem
    20 Tháng Tám, 2022 at 4:42 chiều
    Reply
    (8x-3)(3x+2)-(4x+7)(x+4)=(2x+1)(5x-1)
    <=>8x(3x+2)-3(3x+2)-[4x(x+4)+7(x+4)]=2x(5x-1)+1(5x-1)
    <=>24x^2+16x-9x-6-(4x^2+16x+7x+28)=10x^2-2x+5x-1
    <=>24x^2+7x-6-4x^2-16x-7x-28-10x^2-3x+1=0
    <=>(24x^2-4x^2-10x^2)+(7x-16x-3x-7x)+(-6-28+1)=0
    <=>10x^2-19x-33=0
    <=>10x^2+11x-30x-33=0
    <=>x(10x+11)-3(10x+11)=0
    <=>(x-3)(10x+11)=0
    <=> \(\left[ \begin{array}{l}x-3=0\\10x+11=0\end{array} \right.\) <=>\(\left[ \begin{array}{l}x=3\\10x=-11\end{array} \right.\) <=>\(\left[ \begin{array}{l}x=3\\x=\dfrac{-11}{10}\end{array} \right.\) 
    vậy S={3;-11/10}

Leave a reply

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

Phi Nhung

About Phi Nhung