Toán Lớp 8: tìm x

Question

Toán Lớp 8:  tìm x                                                                                                                                                                                   4x(x-2019)-x+2019=0

diepbich93 · Answer

4x(x-2019)-x+2019=0 <=>4x(x-2019)-(x-2019)=0 <=>(x-2019)(4x-1)=0 <=>[(x-2019=0),(4x-1=0):} <=>[(x=2019),(x=1/4):} Vậy x=2019;x=1/4

quynhthanhnhu · Answer

Answer    4x . (x - 2019) - x + 2019 = 0   => 4x . (x - 2019) - (x - 2019) = 0   => (4x - 1) . (x - 2019) = 0   => $ left[ begin{matrix} 4x - 1 = 0   x - 2019 = 0 end{matrix} right.$   => $ left[ begin{matrix} 4x = 0 + 1   x = 0 + 2019 end{matrix} right.$   => $ left[ begin{matrix} 4x = 1   x = 2019 end{matrix} right.$   => $ left[ begin{matrix} x = 1 : 4   x = 2019 end{matrix} right.$   => $ left[ begin{matrix} x =  dfrac{1}{4}   x = 2019 end{matrix} right.$   $ text{Vậy}$ x  in {1/4 ; 2019}