Question

Tìm x thuộc Z:

\(\dfrac{2x-9}{240}\)=\(\dfrac{39}{80}\)

Answer 1

\(\dfrac{2x-9}{240}\)=\(\dfrac{39}{80}\)\(\Rightarrow\)\(2x-9\)=\(\dfrac{240.39}{80}\)=\(117\)

\(2x-9=117\)\(\Rightarrow\)\(2x=117+9=126\)\(\Rightarrow\)\(x=126:2=63\)

Answer 2

\(\dfrac{2x-9}{240}\)=\(\dfrac{39}{80}\) \(\Rightarrow\) \(2x-9=\)\(\dfrac{240.39}{80}\)=117

\(2x-9=117\)\(\Rightarrow\)\(2x=117-9=108\)\(\Rightarrow\)\(x=108:2=54\)