Answer:

Step-by-step explanation:
Fixed monthly fee = $20
Amount charged per minute for long distance calls = $0.20
denotes total cost such that
minutes are used for long distance calls.
Amount charged for
minutes for long distance calls 
Therefore, an equation for the total cost, C, when N minutes are used for long distance calls is 
Answer:
yes
Step-by-step explanation:
half of $798 is $399. $100 a week × 4 = $400. 400 is very close to 399, so yes it would be a food estimate. Hope this helps! :)
Answer:
13
Step-by-step explanation:
cos(60) =building height / 26
Answer:
54 9/10
Step-by-step explanation:
The perimeter is the sum of all the sides
13 1/4 + 12 1/5 + 18 1/4 + 11 1/5
Add up the whole numbers
13+12+18+11 = 54
1/4+1/5+1/4+1/5
2/4+2/5
1/2+2/5
Get a common denominator
1/2*5/5 + 2/5*2/2
5/10 + 4/10
9/10
Add them back together
54 9/10