91Ó°ÊÓ

Properties of inequalities are written in following table:

To simplify given inequality, use addition and subtraction property of inequalities. Add or subtract same number from both sides does not change inequality as shown below

$\begin{array}{c}11−c≤8\\ 11−c−8+c≤8−8+c\\ 11−8−c+c≤c\\ 3≤c\end{array}$

The solution set of the inequality $3≤c$ contains 3 less than or equal to all real numbers

In interval notation, solution set contains all real number between 3 to $∞$

As $∞$ is not an end points so parentheses is used with it whereas 3 is included in solution set so bracket is used with it.

Solution set is $\left[3,∞\right)$

Assolution set of the inequality $3≤c$ contains 3 less than or equal to all real number

So arrow is towards $∞$ and dot on 3 denotes it is included in the solution set.