The city's budget is $8,000,000. the city actually spends $12,000,000. what is the city's deficit

So with this problem, let's first define the given. The city has a budget of 8m which means that it is willing spend 8m on projects and other things for the city's development. Now when the day arrived that they had to account for their spending, they realized they actually spent 12m instead of the 8m. So to solve for the deficit, meaning the amount outside of the budget, we simply subtract 12m to 8m. If we do this, we will get 4m. So the deficit of the city's budget is 4m. 

Deficit can be found by subtracting how much you spent from how much you actually have.

12,000,000 - 8,000,000 = -4,000,000

The city has a deficit of $-4,000,000.