Hey there! :)
Answer:
2nd choice.
Explanation:
Given:
630 = 42f.
Divide both sides by 42 to solve for f:
630/42 = 42f/42
f = $15.
This equation is not an inequality, so a line would not be graphed on the number-line. The proper way to show a single solution would be with a point. Therefore:
The second choice is correct. The number line has a single point at f = 15.