What is the inverse matrix that can be used to solve this systems of equations

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

step-by-step explanation:

a.   since the profit made in 2012 is equal to the profit made in 2014, the profit is           symmetric about the line y = 120,000.

step-by-step explanation:

given that megan owns a clothing boutique.

the profits of 2010, 11, are recorded and shown as follows:

years since     2010 0     1     2     3       4       5

profits made in 1000's   39       84     111     120   111     84

we find that profit gradually increases form 2010 to 2013 upto 120,   then starts decreasing.

the profits for 2012 and 2014 are the same while that of 2011 and 2015 are also the same.

this shows that there is symmetry about the line profit = 120000

hence answer is:

a.   since the profit made in 2012 is equal to the profit made in 2014, the profit is           symmetric about the line y = 120,000.

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12cm

the answer is d