Answer:
x³ - 10x² + 31x - 30
Step-by-step explanation:
Given
(x - 2)(x - 3)(x - 5) ← expand the second pair of factors using FOIL
= (x - 2)(x² - 8x + 15) ← distribute
= x³ - 8x² + 15x - 2x² + 16x - 30 ← collect like terms
= x³ - 10x² + 31x - 30
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:
![x = 3y](https://tex.z-dn.net/?f=x%20%3D%203y)
![z = y - 10](https://tex.z-dn.net/?f=z%20%3D%20y%20-%2010)
![15x + 40y + 5z = 3100](https://tex.z-dn.net/?f=15x%20%2B%2040y%20%2B%205z%20%3D%203100)
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:
![x = 3y](https://tex.z-dn.net/?f=x%20%3D%203y)
By mail service costs <u>$10 less than at-store</u> service, thus:
![z = y - 10](https://tex.z-dn.net/?f=z%20%3D%20y%20-%2010)
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:
![15x + 40y + 5z = 3100](https://tex.z-dn.net/?f=15x%20%2B%2040y%20%2B%205z%20%3D%203100)
The system is:
![x = 3y](https://tex.z-dn.net/?f=x%20%3D%203y)
![z = y - 10](https://tex.z-dn.net/?f=z%20%3D%20y%20-%2010)
![15x + 40y + 5z = 3100](https://tex.z-dn.net/?f=15x%20%2B%2040y%20%2B%205z%20%3D%203100)
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.
![15x + 40y + 5z = 3100](https://tex.z-dn.net/?f=15x%20%2B%2040y%20%2B%205z%20%3D%203100)
![15(4y) + 40y + 5(y - 10) = 3100](https://tex.z-dn.net/?f=15%284y%29%20%2B%2040y%20%2B%205%28y%20-%2010%29%20%3D%203100)
![60y + 40y + 5y = 3150](https://tex.z-dn.net/?f=60y%20%2B%2040y%20%2B%205y%20%3D%203150)
![105y = 3150](https://tex.z-dn.net/?f=105y%20%3D%203150)
![y = \frac{3150}{105}](https://tex.z-dn.net/?f=y%20%3D%20%5Cfrac%7B3150%7D%7B105%7D)
![y = 30](https://tex.z-dn.net/?f=y%20%3D%2030)
Then
![x = 3y = 3(30) = 90](https://tex.z-dn.net/?f=x%20%3D%203y%20%3D%203%2830%29%20%3D%2090)
The cost of one on-site repair service is of $90.
A similar problem is given at brainly.com/question/24823220
First, you multiply 2.1 by 3.2, which gives you the answer of 6.72. Then, you multiply 10-2 by 10-4. One rule about multiplying exponents, you just add the exponents. So 10-2 x 10-4 = 10-6. Finally you get the answer of C. 6.72 x 10-6.
Answer:
this at all so yea
Step-by-step explanation:
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