Use Matrices to Solve the System of Equations (If Possible)

question 46

Multiple Choice

Use matrices to solve the system of equations (if possible) .Use Gaussian elimination with back-substitution or Gauss-Jordan elimination. ​​ $$\left\{ \begin{array} { r l r } 3 x + 2 y - z + w & = 0 \\x - y + 4 z - w & = 28 \\- 2 x + y + 2 z - w & = 3 \\x + y + z + w & = 8\end{array} \right.$$ ​

• A)​(-3,-2,6,1)
• B)(-3,2,-6,-1)
• C)(3,-2,6,1)
• D)(3,-2,6,-1)
• E)(3,-2,-6,1)

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Definitions:

Actual Results

The real financial or operational outputs of a business, as opposed to projections or estimates.

Variable Overhead Rate Variance

The difference between the actual variable overhead incurred and the expected (or standard) variable overhead allocated, based on activity level.

Lubricants

Substances applied to reduce friction between surfaces in mutual contact, which ultimately reduces the heat generated when the surfaces move.

Variable Manufacturing Overhead

Costs that vary with the level of production output and include expenses such as indirect materials, supplies, and utilities used in manufacturing.