Question

bài 14: Tìm x biết:

a/ \(-\frac{4}{5}-x=2,25\)

b/ \(\left(\frac{2x}{5}-1\right):\left(-5\right)=\frac{1}{7}\)

Answer 1

a.\(\frac{-4}{5}-x=2,25\Leftrightarrow\frac{-4}{5}-x=\frac{9}{4}\Leftrightarrow x=\frac{-61}{20}\)

b. \(\left(\frac{2x}{5}-1\right)\times\frac{-1}{5}=\frac{1}{7}\Leftrightarrow\frac{-2x}{25}+\frac{1}{5}=\frac{1}{7}\Leftrightarrow\frac{-2x}{25}=\frac{-2}{35}\Leftrightarrow x=\frac{5}{7}\)