how can I calculate y=mx+b graphs

The graphs below show the profit, y, of the competitor over the past 16 months. Both graphs show the same information.

Graph A and Graph B both titled profit of competitor have X-axis labeled Months and Y-axis labeled profit in thousands of dollars. Graph A begins from (0, 11) and goes right and slightly up. Graph B begins from (0, 13) and goes right and upward.
Complete the following sentences.

To emphasize the slow increase in profits, it would be best for Bradley to use
for his presentation.

Bradley should use this graph for his presentation because the profit
on this graph.

To emphasize the slow increase in profits, it would be best for Bradley to use Graph A for his presentation.

Bradley should use this graph for his presentation because the profit margin is smaller on this graph.