Question

-45% . x + 2\(\dfrac{3}{8}\) = -1\(\dfrac{31}{40}\)            

Answer 1

\(-45\%x+2\dfrac{3}{8}=-1\dfrac{31}{40}\)

\(\Rightarrow-\dfrac{9}{20}x+\dfrac{19}{8}=-\dfrac{71}{40}\)

\(\Rightarrow-\dfrac{9}{20}x=-\dfrac{71}{40}-\dfrac{19}{8}\)

\(\Rightarrow-\dfrac{9}{20}x=-\dfrac{83}{20}\)

\(\Rightarrow x=-\dfrac{83}{20}:\left(-\dfrac{9}{20}\right)\)

\(\Rightarrow x=\dfrac{83}{9}\)

Vậy \(x=\dfrac{83}{9}\)

Answer 2

\(-45\%x+2\dfrac{3}{8}=-1\dfrac{31}{40}\)

\(\Leftrightarrow\dfrac{9}{20}x+\dfrac{19}{8}=-\dfrac{71}{40}\)

\(\Leftrightarrow\dfrac{9}{20}x=-\dfrac{71}{40}-\dfrac{19}{8}\)

\(\Leftrightarrow\dfrac{9}{20}x=-\dfrac{83}{20}\)

\(\Leftrightarrow x=-\dfrac{83}{20}:\dfrac{9}{20}\)

\(\Leftrightarrow x=-\dfrac{83}{20}.\dfrac{20}{9}\)

\(\Leftrightarrow x=-\dfrac{83}{9}\)