Question 95070
If you need help figuring out how to graph these, let me know, otherwise here is your graphs. 
1.
{{{x>4}}}
{{{graph (300,300,-5,5,-5,5,x>4)}}}

2.
{{{3x>2x-4}}} {{{x>-4}}}
{{{graph (300,300,-5,5,-5,5,x>-4)}}}

3.
{{{7x-21>5x-14}}} {{{2x>7}}} {{{x>3.5}}}
{{{graph (300,300,-5,5,-5,5,x>3.5)}}}