If R={(a,b),(c,d),(e,f)} find domain and range of R and find inverse of R

The line x=15 is the line parallel to the axis OY.
So the paralel lines to the line x=15 are  parallel  to the axis OY, so their equations are  x=a,  where "a"  is a real number. 
Here you've got point (-1,5) so x-coordinate is x=-1, 
So equation this line  is x=-1
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