Question

Tìm x trong các tỉ lệ thức sau:

\(\frac{2x-1}{3}=\frac{7}{27.\left(2x+1\right)}\)

Answer 1

\(\dfrac{2x-1}{3}=\dfrac{7}{27\left(2x+1\right)}\)

\(\Leftrightarrow27\left(4x^2-1\right)=21\)

\(\Leftrightarrow4x^2-1=\dfrac{7}{9}\)

\(\Leftrightarrow4x^2=\dfrac{16}{9}\)

\(\Leftrightarrow x^2=\dfrac{4}{9}\)

=>x=2/3 hoặc x=-2/3