Step-by-step explanation:
The answer is OPTION C
Find the Inverse of a 3x3 Matrix.
First
Find the Determinant of A(The coefficients of e
Proceed towards finding the CO FACTOR of the 3x3 Matrix.
+. - +
A= [ 1 -1 -1 ]
[ -1 2 3 ]
[ 1 1 4 ]
The determinant of this is 1.
Find the co factor
| 2 3 | |-1 3 | |-1 2 |
| 1. 4. | |1 4 | |1. 1 |
|-1. -1 | |1 -1 | |1 -1
| 1. 4 | |1. 4| |1 1|
|-1. -1 | |1 -1 | |1. -1
|2. 3| |-1. 3| |-1 2|
After Evaluating The Determinant of each 2x 2 Matrix
You'll have
[ 5 7 -3]
[3 5 -2 ]
[-1 -2 1]
Reflect this along the diagonal( Keep 5,5 -2)
Then switching positions of other value
No need of Multiplying by the determinant because its value is 1 from calculation.
After this
Our Inverse Matrix Would be
[ 5 3 -1 ]
[7 5 -2 ]
[ -3 -2 1]
THIS IS OUR INVERSE.
SO
OPTION C
(x² + 16)(x² - 16)
= (x²)² - 16²
= x⁴ - 256
Where <em>x </em>is the number of books sold, <em>i </em>is income, and <em>c </em>is cost:
<em>c = 4x + 3500 </em> ($4 per book plus the 3500 flat marketing fee)
<em>i = 15x </em>($15 per book)
You are looking for the point where these intersect: the intersection is where the income is equal to the cost, and at any point after that the income is greater than the cost. So, set the equations equal to each other:
<em>4x + 3500 = 15x </em>
subtract 4x from both sides
<em>3500 = 11x</em>
divide both sides by 11
<em>x = 318.181818</em>
So, you would have to sell a minimum of 319 books in order to make a profit.
Cross multiply
(3x - 1)(4x + 5) = (2x + 6)(6x - 4)
12x^2 + 11x - 5 = 12x^2 + 28x -24
Solve for x
-17x = -19
x = 19/17
Answer:
6(y + 4) = -3(2y - 2) + 8y
6y + 24 = -6y + 6 + 8y
6y + 24 = 2y + 6
Subtract -2y on both sides
4y + 24 = 6
Subtract -24 on both sides
4y = -18
y = - 4.5