Question 957413
{{{ y = 5 }}} is a horizontal line. No matter what you
choose for {{{ x }}}, {{{ y }}} is always {{{ 5 }}}. A 
horizontal line is the only line that does this.
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The slope of any horizontal line is {{{ 0 }}}
Use the general point-slope formula
(2,7)
{{{ ( y - 7 ) / ( x - 2 ) = 0 }}}
{{{ y - 7 = 0 }}}
{{{ y = 7 }}}
This makes sense because this is a horizontal line too
Here's the plot of these lines:
{{{ graph( 400, 400, -10, 10, -2, 10, 5, 7) }}}