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
Answer:
He needs 16 ounces of raisins and 8 ounces of nuts
Step-by-step explanation:
Let
x -----> the number of ounces of raisins
y -----> the number of ounces of nuts
we know that
x+y=24 -----> equation A
x=2y -----> equation B
Solve the system by substitution
Substitute equation B in equation A and solve for y
(2y)+y=24
3y=24
y=8 ounces of nuts
Find the value of x
x=2(8)=16 ounces of raisins
therefore
He needs 16 ounces of raisins and 8 ounces of nuts
Answer:
it would be answer a
Step-by-step explanation:
that's all i have
I believe the correct number is 88.