The two points are .
Two-points form of line equation : .
Substitute in the two-points form of line equation.
The fourth option is correct.
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..![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=e8baa5b4d72ef0a13db90dea272c37dd.png\")
.![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=44cd446e4c950156a58be86180baa0da.png\")
in the two-points form of line equation.![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=de18d94f3ee066d6574226ddd06e4d23.png\")
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=2c6629ae8a20fc07f435a63435cfcb1e.png\")