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
Here you go. Do you think that you could help me with my question
5a – 10b = 45
5a – 10(3) = 45
5a – 30 = 45
+30 +30
5a = 75/5
<span>a = 15</span>
answer ...
to halp you and thank you
Answer:
2c+4d
if c=8 and D=5,
2(8)+4(5)
16+20
=36
Step-by-step explanation:
0.0069
Step-by-step explanation:
6.9 move the decimal 3 places to the left