I need an answer as fast as possible I’ll give you brainlist and I know I’m stupid!

Acar dealership pays you 5% commission on your first $10,000 on car sales and 8% commission on the sale amount over $10,000 if you sold a $12,000 car how much is your commission

Ineed with math stuff it involves graphs

Here is my question! jayne is studying urban planning and finds that her town is decreasing in population by 3% each year. the population of her town is changing by a constant rate.true or false?