Question

Tìm x biết : 

x + 2 / 5 - 2x = 4/7

Answer 1

\(x+\dfrac{2}{5}-2x=\dfrac{4}{7}\)

\(-x+\dfrac{2}{5}=\dfrac{4}{7}\)

\(-x=\dfrac{4}{7}-\dfrac{2}{5}\)

\(x=-\dfrac{6}{35}\)

Answer 2

\(\dfrac{x+2}{5-2x}=\dfrac{4}{7}\)

\(\Leftrightarrow7x+14=20-8x\)

\(\Leftrightarrow15x=6\)

hay \(x=\dfrac{2}{5}\)