Question

cứu vs=)

(242/363+1616/2121)=2/7*x

Answer 1

\(\left(\dfrac{242}{363}+\dfrac{1616}{2121}\right)=\dfrac{2}{7}.x\)

\(\Leftrightarrow\dfrac{242}{363}\left(1+\dfrac{8}{7}\right)=\dfrac{2}{7}.x\)

\(\Leftrightarrow\dfrac{242}{363}.\dfrac{15}{7}=\dfrac{2}{7}.x\)

\(\Leftrightarrow\dfrac{10}{7}=\dfrac{2}{7}.x\)

\(\Leftrightarrow x=\dfrac{10}{7}:\dfrac{2}{7}\)

\(\Leftrightarrow x=\dfrac{10}{7}.\dfrac{7}{2}\)

\(\Leftrightarrow x=5\)

Answer 2

=>x*2/7=(2/3+16/21)=14/21+16/21=30/21=10/7

=>x=5