Exam 4: Graphing and Optimization

Provide an appropriate response. -Use Gauss-Jordan elimination, without introducing fractions, to find the inverse of rse of .

Determine whether B is the inverse of A. -A =

The system cannot be solved by matrix inverse methods. Find a method that could be used and then solve the system. -- 6

Perform the operation, if possible. -Let C = and D and D= . . Find C - 4D.

Answer the question. -Which of the following matrices has an inverse?

State whether the matrix is in reduced form or not in reduced form. -

Perform the operation, if possible. -

Write the linear system corresponding to the reduced augmented matrix. -

Solve the problem. -A Dawn Bakery bakes whole wheat, oat, and rye bread, with mixing, baking, and packaging times, in hours, as shown: An order is received for 400 loaves of whole wheat bread, 200 loaves of oat bread, and 350 loaves of rye bread. Given that the cost of mixing, baking, and packaging is $14, $25, and$2, respectively, per hour, find matrices B and C so that the Product BAC will give the total cost (excluding raw materials) of filling this order. Find the total cost.

Provide an appropriate response. -Solve the matrix equation uation by using the inv by using the inerse of the coefficient matrix.

Find the matrix product mentally, without the use of a calculator or pencil-and-paper calculations. -

Provide an appropriate response. -Use Gauss-Jordan elimination to find the inverse of se of

Identify the row operation that produces the resulting matrix. -

Perform the indicated operations given the matrices. -Let C = and D = ; C - 3D

Find the inverse, if it exists, of the given matrix. -

Write a system of equations associated with the augmented matrix. Do not try to solve. -

Solve the problem. -Sam and Chad are ticket-sellers at their class play. Sam is selling student tickets for $2.00 each, and Chad selling adult tickets for $5.50 each. If their total income for 24 tickets was $83.00, how many tickets did Sam sell?

Write the matrix equation as a system of linear equations without matrices. -

Perform the operation, if possible. -Let A == a and B = . Fi. Fnd AB.

Perform the operation, if possible. --- 2