Using a system of equation, we have that:
a)
- x, which is the cost of on-site service.
- y, which is the cost of at-store service.
- z, which is the cost of by-mail service.
b)
The system is:



c)
The cost of one on-site repair service is of $90.
Item a:
The variables are:
- x, which is the cost of on-site service.
- y, which is the cost of at-store service.
- z, which is the cost of by-mail service.
Item b:
On-site service costs <u>3 times as much as at-store service</u>, thus:

By mail service costs <u>$10 less than at-store</u> service, thus:

Last week, the shop completed <u>15 services on-site, 40 services at-store, and 5 services by mail for total sales of $3100</u>, thus:

The system is:



Item c:
- The cost of one on-site repair service is x.
- First, replacing the first two equations into the third, we find y, and then with it we find x.






Then

The cost of one on-site repair service is of $90.
A similar problem is given at brainly.com/question/24823220
If it is fractions then the answer is -7/15. Think of as 8/15 - 1/15 except the answer is a negative number
Answer:
19$
Step-by-step explanation:
In this problem, we have to apply the rule of three. Also, we must have present that $15.20 is the 80% of the price, because the store offers a 20% of discount. So, if $15.20 is 80%, how much would be the 100%?
Therefore, the original price of the pants is $19.
Remember that we must identified the right proportion to apply the rule of three, in this case, that proportion is the 80% with 15.20, that's the reason or fraction center of the whole operation.
N P r = (n!)/((n-r)!)
8 P 4 = (8!)/((8-4)!)
8 P 4 = (8!)/(4!)
8 P 4 = (8*7*6*5*4!)/(4!)
8 P 4 = 8*7*6*5
8 P 4 = 1680
The final answer is 1680
One pair of opposite sides both parallel and congruent implies a parallelogram.