Question

Tìm x :

\(\dfrac{1}{2}\). x +\(\dfrac{3}{5}\) . (x - 2) = 3

Answer 1

\(\dfrac{1}{2}x+\dfrac{3}{5}\left(x-2\right)=3\)

\(\Leftrightarrow\dfrac{1}{2}x+\dfrac{3}{5}x-\dfrac{6}{5}=3\)

\(\Leftrightarrow\dfrac{1}{2}x+\dfrac{3}{5}x=3+\dfrac{6}{5}\)

\(\Leftrightarrow\dfrac{11}{5}x=\dfrac{21}{5}\)

\(\Rightarrow x=\dfrac{21}{5}:\dfrac{11}{5}=\dfrac{21}{5}.\dfrac{5}{11}=\dfrac{21}{11}\)

Answer 2

\(\dfrac{1}{2}x+\dfrac{3}{5}\left(x-2\right)=3\)

\(\Rightarrow\dfrac{1}{2}x+\dfrac{3}{5}x-\dfrac{6}{5}=3\)

\(\Rightarrow\dfrac{1}{2}x+\dfrac{3}{5}x=\dfrac{21}{5}\Rightarrow\left(\dfrac{1}{2}+\dfrac{3}{5}\right)x=\dfrac{21}{5}\)

\(\Rightarrow\dfrac{11}{10}x=\dfrac{21}{5}\Rightarrow x=\dfrac{21}{5}.\dfrac{10}{11}=\dfrac{42}{11}\)