I can’t math :’( I need help !!!

Can someone me with my hwplz(only the circled ones)

An equation representing lyle’s hedge-trimming business is a = 12n - 300 where a is the amount of profit or loss in dollars and n is the number of hedges trimmed. how would the graph of lyle’s business change if the equation a = 10n - 300 represented his business? the graph would be flatter. the graph would be steeper. the graph would start closer to the origin. the graph would start lower on the y-axis.

Somone me i want to know what 18 hours out of 24 hours in a fraction