Answer:
w=-7/2z
Step-by-step explanation:
to solve for w you firstly have to group the like terms
5w-3w=2z-9z
2w=-7z
then you have to divide both sides by 2 inorder to remain with w on one side.
2w/2=-7/2
w=-7/2
I hope this helps
17/10
or 1 7/10
i did it on my calculator lol
Answer:

Step-by-step explanation:
Total number of toll-free area codes = 6
A complete number will be of the form:
800-abc-defg
Where abcdefg can be any 7 numbers from 0 to 9. This holds true for all the 6 area codes.
Finding the possible toll free numbers for one area code and multiplying that by 6 will give use the total number of toll free numbers for all 6 area codes.
Considering: 800-abc-defg
The first number "a" can take any digit from 0 to 9. So there are 10 possibilities for this place. Similarly, the second number can take any digit from 0 to 9, so there are 10 possibilities for this place as well and same goes for all the 7 numbers.
Since, there are 10 possibilities for each of the 7 places, according to the fundamental principle of counting, the total possible toll free numbers for one area code would be:
Possible toll free numbers for 1 area code = 10 x 10 x 10 x 10 x 10 x 10 x 10 = 
Since, there are 6 toll-free are codes in total, the total number of toll-free numbers for all 6 area codes = 
Counting by Tens with numbers
10, 20, 30, 40, 50, 60, 70, 80, 90
Counting by Tens with words
ten, twenty, thirty, forty, fifty, sixty, seventy, eighty, ninety, one hundred
Number Patterns when counting by Tens
When you count by tens the numbers create a pattern. All the numbers end with a zero. The first digits are just like the numbers when you count (1, 2, 3, 4, 5, etc.). This pattern gives the numbers 10, 20, 30, 40, 50, etc.
found from: http://www.aaamath.com/k4c_cox1.htm
1.55 us gallons.
hope i could help!
Thunderclan89