Answer:
The answer is below
Step-by-step explanation:
Let x represent the number of small hat purchased, y represent the number of medium hat purchased and z represent the number of large hat purchased.
Since a total of 47 hats where purchased, hence:
x + y + z = 47 (1)
Also, he spent a total of $302, hence:
5.5x + 6y + 7z = 302 (2)
He purchases three times as many medium hats as small hats, hence:
y = 3x
-x + 3y = 0 (3)
Represent equations 1, 2 and 3 in matrix form gives:
![\left[\begin{array}{ccc}1&1&1\\5.5&6&7\\-3&1&0\end{array}\right] \left[\begin{array}{c}x\\y\\z\end{array}\right] = \left[\begin{array}{c}47\\302\\0\end{array}\right] \\\\\\\\ \left[\begin{array}{c}x\\y\\z\end{array}\right] =\left[\begin{array}{ccc}1&1&1\\5.5&6&7\\-3&1&0\end{array}\right] ^{-1} \left[\begin{array}{c}47\\302\\0\end{array}\right] \\\\\\ \left[\begin{array}{c}x\\y\\z\end{array}\right] = \left[\begin{array}{c}6\\18\\23\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D1%261%261%5C%5C5.5%266%267%5C%5C-3%261%260%5Cend%7Barray%7D%5Cright%5D%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bc%7Dx%5C%5Cy%5C%5Cz%5Cend%7Barray%7D%5Cright%5D%20%3D%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bc%7D47%5C%5C302%5C%5C0%5Cend%7Barray%7D%5Cright%5D%20%5C%5C%5C%5C%5C%5C%5C%5C%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bc%7Dx%5C%5Cy%5C%5Cz%5Cend%7Barray%7D%5Cright%5D%20%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D1%261%261%5C%5C5.5%266%267%5C%5C-3%261%260%5Cend%7Barray%7D%5Cright%5D%20%5E%7B-1%7D%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bc%7D47%5C%5C302%5C%5C0%5Cend%7Barray%7D%5Cright%5D%20%5C%5C%5C%5C%5C%5C%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bc%7Dx%5C%5Cy%5C%5Cz%5Cend%7Barray%7D%5Cright%5D%20%3D%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bc%7D6%5C%5C18%5C%5C23%5Cend%7Barray%7D%5Cright%5D)
Therefore he purchases 6 small hats, 18 medium hats and 23 large hats
Answer: C
Step-by-step explanation:
The process of expressing w in terms of A and l is called transposition or changing the subject of the formula. The methods used to change the subject of the formula are the same as those used for solving equations.
It must be 5 (a) because it’s 4
Answer: <em>n </em>-<em> 4 = -15</em>
<em>n </em>= -11
Step-by-step explanation:
If -15 is the same as 4 less than <em>n, </em>that means that <em>n </em>- 4 = -15
Then you add 4 to each side of the equation to get <em>n </em>by itself. (-15 + 4 = -11)
That step leaves you with <em>n</em> = -11
