$\"\"$

\

The inequality is $\"\"$

\

(Subtract 8 from each side)

\

$\"\"$

\

$\"\"$

\

(Divide each side by 5)

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

Check: To check the solution Substitute r=-7 in the equation.

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

Hence proved