Question

cal 1 problem
-.5<(1/x)-(1/5)<.5
-.3<1/x<.7
-3.33 12 years ago

Answer 1

$$ -.5<\frac{1}{x}-\frac{1}{5}<.5\\ \frac{-1}{2}<\frac{1}{x}-\frac{1}{5}<\frac{1}{2}\\
\frac{-1}{2}+\frac{1}{5}<\frac{1}{x}<\frac{1}{2}+\frac{1}{5}\\
\frac{-3}{10}<\frac{1}{x}<\frac{7}{10}\\
\frac{1}{x}<\frac{7}{10}\rightarrow \frac{1}{x}-\frac{7}{10}<0 \\
\frac{-3}{10}<\frac{1}{x}\rightarrow 0<\frac{1}{x}+\frac{3}{10}\\
$$