Question 176921
1. You plug the solution in and see if it satifies the inequality.
2. It's not. The only issue is that while an equation has a finite number of solutions, an inequality has an infinite number of solutions. 
As an example,
{{{x-1=0}}} has 1 solution, {{{x=1}}}.
{{{x-1>=0}}} has an infinite number of solutions, {{{x>=1}}}. 
3. The only time that happens is when you have the inequality sign of "greater than or equal to" and "less than or equal to" because of the "or equal to" part.
We can once again use the previous case. 
{{{x-1=0}}} has 1 solution, {{{x=1}}}.
{{{x-1>=0}}} has an infinite number of solutions, {{{x>=1}}}. 
This would not be the case with < or > inequality signs. 
{{{x-1=0}}} has 1 solution, {{{x=1}}}.
{{{x-1>0}}} has an infinite number of solutions, {{{x>1}}} (not including {{{x=1}}}).