Question 324833
Any point on the line y= -5 will have a y coordinate of -5. So two points are (0,-5) and (3,-5). Plot them to get


{{{ drawing(500, 500, -10, 10, -10, 10,
 grid(1),
 graph( 500, 500, -10, 10, -10, 10,0),
 circle(0,-5,0.05),circle(0,-5,0.08),circle(0,-5,0.10),
 circle(3,-5,0.05),circle(3,-5,0.08),circle(3,-5,0.10)
)}}}



Now draw a straight line through the two points to graph y = -5


{{{ drawing(500, 500, -10, 10, -10, 10,
 grid(1),
 graph( 500, 500, -10, 10, -10, 10,0,-5),
 circle(0,-5,0.05),circle(0,-5,0.08),circle(0,-5,0.10),
 circle(3,-5,0.05),circle(3,-5,0.08),circle(3,-5,0.10)
)}}}


Graph of {{{y=-5}}} (green horizontal line)