\(\Leftrightarrow\dfrac{x}{2}=\dfrac{1}{14}+4=\dfrac{57}{14}\Leftrightarrow x=\dfrac{57}{7}\)
\(\dfrac{1}{2}x-4=\dfrac{2}{28}\\ \Leftrightarrow\dfrac{1}{2}x=\dfrac{2}{28}+4\\ \Leftrightarrow\dfrac{1}{2}=\dfrac{4\times28+2}{28}\\ \Leftrightarrow\dfrac{1}{2}x=\dfrac{114}{28}\\ \Leftrightarrow x=\dfrac{114}{28}:\dfrac{1}{2}\\ \Leftrightarrow x=\dfrac{114}{28}\times2=\dfrac{228}{28}\\ \Leftrightarrow x=\dfrac{57}{7}\)
1/2x-4=2/28
1/2x=2/18+4
1/2x=114/28
x=114/28:1/2
x=228/28
x=57/7
vậy x=57/7
