$\"\"$

The word $\"\"$ difference $\"\"$ represent the addition operation and its symbol is $\"\"$ .

The word $\"\"$ less than $\"\"$ represent the symbol is $\"\"$ .

The word $\"\"$ the difference of c and 13 is less than $\"\"$ $\"\"$ represents the inequality is $\"\"$ . $\"\"$

The inequality is $\"\"$ and solve for n.

Add 13 to each side.

$\"\"$

The solution of the inequality is $\"\"$ and its graph is

$\"grph$

The open circle means that $\"\"$ is not a solution of the inequality. $\"\"$

The solution of the inequality $\"\"$ is $\"\"$ and its graph is

$\"grph$