(12/5-x):5/7=12/5
=>12/5-x=12/5x5/7
=>12/5-x=12/7
=>x=12/5-12/7
=>x=24/35
Vậy...
\((\dfrac{12}{5} - x) : \dfrac{5}{7} = \dfrac{12}{5}\)
\( \dfrac{12}{5} - x = \dfrac{12}{5} . \dfrac{5}{7}\)
\(\dfrac{12}{5} - x = \dfrac{12}{7}\)
\(x = \dfrac{12}{5} - \dfrac{12}{7}\)
\(x = \dfrac{24}{35}\)
Vậy \( x = \dfrac{24}{35}\)