To find K, we must use the fact that
on the day 200 books were printed
the average cost was $ 9 per book.
Thus, substituting the values, we have:
c (x) = (5.5x + k) / (x)
9 = (5.5 (200) + k) / (200)
Clearing K
(200) * 9 = 5.5 (200) + k
k = (200) * 9 - 5.5 * (200)
k = 700
answer
the value of the constant k is 700
Answer:
![\left[\begin{array}{ccc}5&7\\5&-8\\3&-9\end{array}\right] \left[\begin{array}{ccc}c\\d\end{array}\right] =\left[\begin{array}{ccc}-16\\3\\-15\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D5%267%5C%5C5%26-8%5C%5C3%26-9%5Cend%7Barray%7D%5Cright%5D%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Dc%5C%5Cd%5Cend%7Barray%7D%5Cright%5D%20%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D-16%5C%5C3%5C%5C-15%5Cend%7Barray%7D%5Cright%5D)
This tells us that:
![A=\left[\begin{array}{ccc}5&7\\5&-8\\3&-9\end{array}\right]](https://tex.z-dn.net/?f=A%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D5%267%5C%5C5%26-8%5C%5C3%26-9%5Cend%7Barray%7D%5Cright%5D)
![b=\left[\begin{array}{ccc}-16\\3\\-15\end{array}\right]](https://tex.z-dn.net/?f=b%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D-16%5C%5C3%5C%5C-15%5Cend%7Barray%7D%5Cright%5D)
Step-by-step explanation:
So we are saying we have scalars, c and d, such that:
![c\left[\begin{array}{ccc}5\\5\\ 3\end{array}\right]+d\left[\begin{array}{ccc}7\\-8\\-9\end{array}\right]=\left[\begin{array}{ccc}-16\\3\\-15\end{array}\right]](https://tex.z-dn.net/?f=c%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D5%5C%5C5%5C%5C%203%5Cend%7Barray%7D%5Cright%5D%2Bd%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D7%5C%5C-8%5C%5C-9%5Cend%7Barray%7D%5Cright%5D%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D-16%5C%5C3%5C%5C-15%5Cend%7Barray%7D%5Cright%5D)
.
So we want to find a way to express this as:
Ax=b where x is the scalar vector, ![\left[\begin{array}{ccc}c\\d\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Dc%5C%5Cd%5Cend%7Barray%7D%5Cright%5D)
.
So we can write this as:
90% of what is 63....
0.90x = 63
x = 63 / 0.90
x = 70....so 70 ppl work at stalling printing
5(6x+5)-2(4x-1) = 30x+25-8x+2 = 22x+27
