$\"\"$

\

The inequality is $\"\"$

\

(Add 13 to each side)

\

$\"\"$

\

$\"\"$

\

(Subtract $\"\"$ from each side )

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

Check: To check the solution Substitute $\"\"$ in the equation.

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

Hence proved