MULTIPLE CHOICE.  Choose the one alternative that best completes the statement or answers the question.

Write the requested matrix for the system of equations.

1)     w + x +  y z =                   Write the augmented matrix.

 2w -   x           z =

 -w - 2x y          =

 

A)    B)     

C)    D)     

 

Write the system of equations associated with the augmented matrix. Do not solve.

2) 

 

A) x         - z  =

     -3y       =

             2z = B)  x         - z  =

          -3z  =

             2z =

C) x                   =

       -3y        =

 -x      +   2z = D)  x   -  y                  =

     -3y       =

             2z =

 

Find the system of equations that models the problem. Do not solve.

3)  A department of a  factory hires semiskilled workers, skilled workers, and managers.  Each semi skilled worker is paid $10 per hour, each skilled worker is paid $ per hour,  and each manager is paid $25 per hour.  The department is allowed an hourly payroll of $2930 for these three types of workers. Each worker must spend some time in training each week:  semiskilled workers 4 hours , skilled workers 5 hours, and managers 2 hours. The training center can handle a maximum of 1050 person-hours each week. The department needs 230 skilled and semiskilled workers to meet production schedules. Assumung that the allowable payroll is met, the training center is fully utilized, and production needs are met, how many of each type of worker does the department need?

Let x represent the number of semiskilled workers, y the number of skilled workers, and z the number of managers.

 

A) 10x + 4y = 2930

x + 5y  = 1050

25y + 2z = 230 B)  10x + 25y + 13z = 2930

4x + 5y + 2z = 1050

x + y = 230

C) 10x + y + 25z = 2930

4x + 5y + 2z = 1050

x + y = 230 D)  10x + y + 25z = 2930

4x + 5y  = 1050

x + y + z = 230

 

Perform the row operations on the matrix and write the resulting matrix.

4)   Replace by +

  

A)

 B)  

 C)  

 D)  

 

 

5)  Replace  by

 

 

A)

 B)  

 C)  

 D)  

  

 

Use the pivoting process to put the augmented matrix into reduced row-echelon form.

6) 

 

A)   B)      

C)  D)     

 

Solve the system.

7)  x +   y =

x y =

A) (, ) B)  No solution C)  (, ) D)  (, )

 

Use the Gauss-Jordan method to solve the system of equations.

8)  2x - 2y + 3z =

  x + 2y - z =

         2y + z =  

A) (, , ) B)  (, , ) C)  No solution D)  (, , )

 

9)   x - y + 8z = -107

     x + 2y = 21

2x + y + 8z = -80

A) (5, 8, -13) B)  (5, 8, 0) C)  No solution D)  (5, 8, 7)

 

Solve the problem by writing and solving a suitable system of equations.

10)  Julia is preparing a meal by combining three ingredients. One unit of each ingredient provides the following quantities (in grams) of carbohydrates, fat, and protein.

 

                                           Protein(g)         Carbohydrates(g)         Fat (g)

        Ingredient A                     3                              3                             1

        Ingredient B                      2                              4                             2

        Ingredient C                      4                              5                             1

 

Ideally the meal should contain  of protein,  of carbohydrates, and  of fat. How many units of each ingredient should Julia use?

A)  grams of ingredient A,  grams of ingredient B,  grams of ingredient C

B)  grams of ingredient A,  grams of ingredient B,  grams of ingredient C

C)  grams of ingredient A,  grams of ingredient B,  grams of ingredient C

D)  grams of ingredient A,  grams of ingredient B,  grams of ingredient C

 

Find the solutions, if any exist. Write the solutions in parametric form.

11)  x -  y - 5z =

       y + 3z =

x + y +   z =  

A) (0, 0, )

B) x = 2z + , y = -3z + , z = any real number

C) x = 3z + , y = -3z + , z = any real number

D) x = 2z - , y = -3z - , z = any real number

 

12)  y + z =

-x + z =

x + y  =  

A) x = z - , y =  - z, z = any real number

B) x =  , y = , z = 0

C) x = z - , y =  + z, z = any real number

D) x = z + , y =  - z, z = any real number

 

13)  x +   y +   z =  9

2x - 3y + 4z =  7

A) x = , y = , z = any number

B) x = , y = , z = any number

C) x = , y = , z = any number

D) x = , y = , z = any number

 

Solve the problem by writing and solving a suitable system. Write the solution in parametric form.

14)  A school library has $ to spend on new books among the four categories of biology, chemistry, physics, and mathematics. If the amount spent on biology books is to be the same as the amount spent on chemistry books and if the amount spent on mathematics books is to be the same as the total spent on chemistry and physics books, how can the money be distributed among the four types of books? (Let x denote the amount spent on biology books, y the amount spent on chemistry books, z the amount spent on physics books, and w the amount spent on mathematics books.)

A) x = $ - w, y = $ - w, z = 2w - $,  

B) x = $ + w, y = $ + w, z = w - $,  

C) x = $ - 2w, y = $ - 2w, z = 3w - $,   

D) x = $ - 3w, y = $ - 3w, z = 4w - $,  


 

MULTIPLE CHOICE.  Choose the one alternative that best completes the statement or answers the question.

1)  D

ID: FM3Yc1-5 2.1.1-9

Objective: Write Augmented/Coefficient Matrix Given System                       

 

2)  A

ID: FM3Yc1-5 2.1.2-4

Objective: Write System of Equations Given Augmented Matrix

 

3)  C

ID: FM3Yc1-5 2.1.3-6

Objective: Solve Apps: Find System of Eqns to Model Problem (Miscellaneous)

 

4)  B

ID: FM3Yc1-5 2.2.1-4

Objective: Perform Row Operations on Augmented  Matrix

 

5)  C

ID: FM3Yc1-5 2.2.1-5

Objective: Perform Row Operations on Augmented  Matrix

 

6)  C

ID: FM3Yc1-5 2.2.2-3+

Objective: Transform Augmented  Matrix to Reduced Row-Echelon Form

 

7)  C

ID: FM3Yc1-5 2.2.3-1

Objective: Solve System  in Two Variables by Gauss Jordan

 

8)  A

ID: FM3Yc1-5 2.2.4-8

Objective: Solve System in Three Variables by Gauss Jordan (One Solution)

 

9)  C

ID: FM3Yc1-5 2.2.5-6

Objective: Solve System in Three Variables by Gauss Jordan (No Solution)

 

10)  A

ID: FM3Yc1-5 2.2.7-6

Objective: Solve Apps: Solve System of Equations I

 

11)  B

ID: FM3Yc1-5 2.3.1-1

Objective: Solve Dependent System in Three Variables I

 

12)  A

ID: FM3Yc1-5 2.3.2-3

Objective: Solve Dependent System in Three Variables II

 

13)  A

ID: FM3Yc1-5 2.3.2-4

Objective: Solve Dependent System in Three Variables II

 

14)  C

ID: FM3Yc1-5 2.3.7-5

Objective: Solve Apps: Linear Systems with Many Solutions