Answer:
Slope is 1/2
Step-by-step explanation:
Answer: $2,000
To calculate the max amount you should owe, multiply the credit limit by 80%. $2,500 * 80% = 2,000
The given formula 
Solve for y means we have to make y alone
\\
Add -10 on both sides, we get

As there is multiplication sign between r and y so to solve for y, divide both side by r

Can't see the graph can you make it more clear?
N+4=13
-4 -4
n = 9
the sum of a number(n) and 4 that is no larger than 13 is 9