Solving Linear Systems with Matrix Inverses

Solving Systems w/Matrices

Flex Learning Day Assignment

Systems of Eqns with Matrices

Notice the eqns are written in standard form. Every coefficient must be represented and in the corresponding row and column. If a variable is not present in an eqn, the coefficient would be ZERO.

Can't Divide by a Matrix

Instead of dividing by the coefficient matrix, A, MULTIPLY BY THE INVERSE to solve for the variable matrix, X

It is ALWAYS the inverse of the coefficient matrix multiplied by the constant matrix.

Multiple Choice

Write the matrix equation for the system.

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Find the determinant for the coefficient matrix.

Multiple Choice

Use the determinant of -7 to find the inverse for the matrix.

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Multiply the inverse by the constant matrix to solve for x.

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Multiply the inverse by the constant matrix to solve for y.

Multiple Choice

Identify the coefficient matrix for the following system.

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At a local movie theater, a person purchased 2 large popcorn and 4 large drinks for a total of $38.50 before taxes. A second person purchased 1 large popcorn and 3 large drinks for $25.10 before taxes at the same theater. How much is the theater charging for large popcorn?(Use a matrix equation to solve)

Fill in the Blank

At a local movie theater, a person purchased 2 large popcorn and 4 large drinks for a total of $38.50 before taxes. A second person purchased 1 large popcorn and 3 large drinks for $25.10 before taxes at the same theater. How much is the theater charging for large drink?(Use a matrix equation to solve)