Answer: (6, -1)
Step-by-step explanation:
Plug each pair in:
3(6)+7(-1)=11
11=11
True, so the first pair works.
-2/(a+b)
Explanation: you are dividing negative two by the sum of a and b so you would put a+b in parentheses as the denominator and then put -2 as the numerator
Answer:
18. 3.3years
Step-by-step explanation:
18. 20,000 - (20,000 - .15x) = 10,000
15% of 20,000 is 3,000
Answer:

Step-by-step explanation:
Know that: 
Starting for (0,0) count how many times you go up to the marked line (which is 2)

The [+] 2 is where you would start off at on the graph, with 1/2 being the slope go up one and over two.
Part. %
------ = -------
Whole 100
816. X
------- = ------
850. 100
850x=81600
-------- ---------
850. 850
X=96
96% of seats were sold