It`s easy.
Real axis (-4) is the abscissa, the part with i (-8) is the ordinate. That`s why...
Just letting you know, you don’t have a picture attached to your problem so unfortunately no one can help you.
Since he gets 10$ per shirt, his revenue is 10y if y represents the shirts sold as he adds 10$ with every purchase. His expenses start with the base cost of 1500, then he also has to pay 3 dollars for each shirt, so his expenses add up to 1500+3y. Since he wants to make as much as he spent, his revenue has to equal his expenses and 10y=1500+3y. Subtracting 3y from both sides, we get 7y=1500. Dividing both sides by 7, we get y=214.something=215 by rounding up
