Question 806695
Being parallel to the x-axis means that no matter
what value of x that you see on the line, the value 
of y never changes 
You are given the point (-1,-7), but you can also say
the line passes through ( x,-7) where x is any value 
you care to choose
The equation of the line is {{{ y = -7 }}}
Here's the plot:
{{{ graph( 400, 400, -20, 20, -10, 2, -7 ) }}}