The answer depends on whether it is a distance-time graph, speed-time graph or something else.
a bar graph
the gradient of a graph at any point.
The answer is 3 ;)
I would probably use a line graph. That would be easiest to find a compare trends (changes over time)...
This would use a bar graph.
The equation you have given, y + 2 = 7, does not describe a line, it describes the number 5. You would not graph a single number, there is nothing to graph.
A line graph is the best graph.
Bar graph.
interval to use for a range of 12 to 39 for a bar graph
bar graph
circle graph
Im guessing that this is a distance over time graph. if so, the gradient of the line of best fit would have a low value. (not be very steep)