Tìm x, biết: (x - 4/5) : 1/2 = -8/5 A. x = 0; B. x = 1; C. x = -1; D. x = 2
Giải thích
Đáp án đúng là: A
Ta có: \({\rm{ }}\left( {x{\rm{ }} - {\rm{ }}\frac{4}{5}} \right){\rm{ : }}\frac{1}{2}{\rm{ = }}\frac{{ - {\rm{ }}8}}{5}\)
\({\rm{x }} - {\rm{ }}\frac{4}{5}{\rm{ = }}\frac{{ - {\rm{ }}8}}{5}{\rm{ }}{\rm{. }}\frac{1}{2}\)
\({\rm{x }} - {\rm{ }}\frac{4}{5}{\rm{ = }}\frac{{ - {\rm{ 4}}}}{5}\)
\({\rm{x = }}\frac{{ - {\rm{ 4}}}}{5}{\rm{ + }}\frac{4}{5}{\rm{ }}\)
\({\rm{x = }}\frac{{ - {\rm{ 4 + 4}}}}{5}{\rm{ }}\)
\(x = \frac{0}{5}\)
x = 0
Vậy x = 0.