Math Test 4 SCORE 97.5 Percent

1.      Use Gaussian elimination to find the complete solution to each system.

x1 + 4x2 + 3x3 - 6x4 = 5
x1 + 3x2 + x3 - 4x4 = 3
2x1 + 8x2 + 7x3 - 5x4 = 11
2x1 + 5x2 - 6x4 = 4

 

A. {(-47t + 4, 12t, 7t + 1, t)}

B. {(-37t + 2, 16t, -7t + 1, t)}

C. {(-35t + 3, 16t, -6t + 1, t)}

D. {(-27t + 2, 17t, -7t + 1, t)}

 

 

2.      Use Cramer's Rule to solve the following system.

x + y + z = 0
2x - y + z = -1
-x + 3y - z = -8

 

A. {(-1, -3, 7)}

B. {(-6, -2, 4)}

C. {(-5, -2, 7)}

D. {(-4, -1, 7)}

 

 

3.      Use Cramer's Rule to solve the following system.

2x = 3y + 2
5x = 51 - 4y

 

A. {(8, 2)}

B. {(3, -4)}

C. {(2, 5)}

D. {(7, 4)}

 

 

4.      Give the order of the following matrix; if A = [aij], identify a32 and a23.

1
 
0
 
-2

-5
 
7

  1/2


 
-6

  11

e
 
-∏

  -1/5

 

A. 3 * 4; a32 = 1/45; a23 = 6

B. 3 * 4; a32 = 1/2; a23 = -6

C. 3 * 2; a32 = 1/3; a23 = -5

D. 2 * 3; a32 = 1/4; a23 = 4

 

5.      Solve the following system of equations using matrices. Use Gaussian elimination with back substitution or Gauss-Jordan elimination.

2x - y - z = 4
x + y - 5z = -4
x - 2y = 4

 

A. {(2, -1, 1)}

B. {(-2, -3, 0)}

C. {(3, -1, 2)}

D. {(3, -1, 0)}

 

 

 

6.      Use Cramer's Rule to solve the following system.

x + 2y + 2z = 5
2x + 4y + 7z = 19
-2x - 5y - 2z = 8

 

A. {(33, -11, 4)}

B. {(13, 12, -3)}

C. {(23, -12, 3)}

D. {(13, -14, 3)}

 

7.      Use Gaussian elimination to find the complete solution to the following system of equations, or show that none exists.

2w + x - y = 3
w - 3x + 2y = -4
3w + x - 3y + z = 1
w + 2x - 4y - z = -2

 

A. {(1, 3, 2, 1)}

B. {(1, 4, 3, -1)}

C. {(1, 5, 1, 1)}

D. {(-1, 2, -2, 1)}

 

 

8.      Solve the following system of equations using matrices. Use Gaussian elimination with back substitution or Gauss-Jordan elimination.

x + y - z = -2
2x - y + z = 5
-x + 2y + 2z = 1

 

A. {(0, -1, -2)}

B. {(2, 0, 2)}

C. {(1, -1, 2)}

D. {(4, -1, 3)}

 

 

9.      Solve the following system of equations using matrices. Use Gaussian elimination with back substitution or Gauss-Jordan elimination.

x + 2y = z - 1
x = 4 + y - z
x + y - 3z = -2

 

A. {(3, -1, 0)}

B. {(2, -1, 0)}

C. {(3, -2, 1)}

D. {(2, -1, 1)}

 

10.  Use Cramer's Rule to solve the following system.

4x - 5y - 6z = -1
x - 2y - 5z = -12
2x - y = 7

 

A. {(2, -3, 4)}

B. {(5, -7, 4)}

C. {(3, -3, 3)}

D. {(1, -3, 5)}

 

11.  If AB = -BA, then A and B are said to be anticommutative.

Are A =

0

1

  -1

0

and B =

1

0

0

  -1

anticommutative?

 

A. AB = -AB so they are not anticommutative.

B. AB = BA so they are anticommutative.

C. BA = -BA so they are not anticommutative.

D. AB = -BA so they are anticommutative.

 

 

12.  Use Cramer's Rule to solve the following system.
 

4x - 5y = 17
2x + 3y = 3

 

A. {(3, -1)}

B. {(2, -1)}

C. {(3, -7)}

D. {(2, 0)}

 

 

13.  Solve the following system of equations using matrices. Use Gaussian elimination with back substitution or Gauss-Jordan elimination.
 

3x1 + 5x2 - 8x3 + 5x4 = -8
 x1 + 2x2 - 3x3 + x4 = -7
2x1 + 3x2 - 7x3 + 3x4 = -11
4x1 + 8x2 - 10x3+ 7x4 = -10

 

A. {(1, -5, 3, 4)}

B. {(2, -1, 3, 5)}

C. {(1, 2, 3, 3)}

D. {(2, -2, 3, 4)}

 

14.  Solve the system using the inverse that is given for the coefficient matrix.

2x + 6y + 6z = 8
2x + 7y + 6z =10
2x + 7y + 7z = 9


The inverse of:

2

2

2

  6

7

7

  6

6

7


is

7/2

-1

0

  0

1

-1

  -3

0

1

 

A. {(1, 2, -1)}

B. {(2, 1, -1)}

C. {(1, 2, 0)}

D. {(1, 3, -1)}

 

15.  Solve the following system of equations using matrices. Use Gaussian elimination with back substitution or Gauss-Jordan elimination.

x - 2y + z = 0
y - 3z = -1
2y + 5z = -2

 

A. {(-1, -2, 0)}

B. {(-2, -1, 0)}

C. {(-5, -3, 0)}

D. {(-3, 0, 0)}

 

16.  Solve the following system of equations using matrices. Use Gaussian elimination with back substitution or Gauss-Jordan elimination.

x + y + z = 4
x - y - z = 0
x - y + z = 2

 

A. {(3, 1, 0)}

B. {(2, 1, 1)}

C. {(4, 2, 1)}

D. {(2, 1, 0)}

 

17.  Use Gaussian elimination to find the complete solution to the following system of equations, or show that none exists.

w - 2x - y - 3z = -9
w + x - y = 0
3w + 4x + z = 6
2x - 2y + z = 3

 

A. {(-1, 2, 1, 1)}

B. {(-2, 2, 0, 1)}

C. {(0, 1, 1, 3)}

D. {(-1, 2, 1, 1)}

 

18.  Use Gauss-Jordan elimination to solve the system.

-x - y - z = 1
4x + 5y = 0
y - 3z = 0

 

A. {(14, -10, -3)}

B. {(10, -2, -6)}

C. {(15, -12, -4)}

D. {(11, -13, -4)}

 

19.  Find values for x, y, and z so that the following matrices are equal.

2x

z

  y + 7

4

 = 

-10

6

  13

4

 

A. x = -7; y = 6; z = 2

B. x = 5; y = -6; z = 2

C. x = -3; y = 4; z = 6

D. x = -5; y = 6; z = 6

 

 

20.  Use Cramer's Rule to solve the following system.
 

x + y = 7
x - y = 3

 

A. {(7, 2)}

B. {(8, -2)}

C. {(5, 2)}

D. {(9, 3)}

 

 

21.  Find the standard form of the equation of the following ellipse satisfying the given conditions.

Foci: (-5, 0), (5, 0)
Vertices: (-8, 0), (8, 0)

A. x2/49 + y2/ 25 = 1

B. x2/64 + y2/39 = 1

C. x2/56 + y2/29 = 1

D. x2/36 + y2/27 = 1

 

 

22.  Find the focus and directrix of each parabola with the given equation.

x2 = -4y

A. Focus: (0, -1), directrix: y = 1

B. Focus: (0, -2), directrix: y = 1

C. Focus: (0, -4), directrix: y = 1

D. Focus: (0, -1), directrix: y = 2

 

 

23.  Find the standard form of the equation of each hyperbola satisfying the given conditions.

Foci: (-4, 0), (4, 0)
Vertices: (-3, 0), (3, 0)

A. x2/4 - y2/6 = 1

B. x2/6 - y2/7 = 1

C. x2/6 - y2/7 = 1

D. x2/9 - y2/7 = 1

 

 

24.  Find the vertex, focus, and directrix of each parabola with the given equation.

(y + 1)2 = -8x

A. Vertex: (0, -1); focus: (-2, -1); directrix: x = 2

B. Vertex: (0, -1); focus: (-3, -1); directrix: x = 3

C. Vertex: (0, -1); focus: (2, -1); directrix: x = 1

D. Vertex: (0, -3); focus: (-2, -1); directrix: x = 5

 

25.  Find the solution set for each system by finding points of intersection.

x2 + y2 = 1
x2 + 9y = 9

 

A. {(0, -2), (0, 4)}

B. {(0, -2), (0, 1)}

C. {(0, -3), (0, 1)}

D. {(0, -1), (0, 1)}

 

 

 

26.  Find the vertex, focus, and directrix of each parabola with the given equation.

(y + 3)2 = 12(x + 1)

A. Vertex: (-1, -3); focus: (1, -3); directrix: x = -3

B. Vertex: (-1, -1); focus: (4, -3); directrix: x = -5

C. Vertex: (-2, -3); focus: (2, -4); directrix: x = -7

D. Vertex: (-1, -3); focus: (2, -3); directrix: x = -4

 

 

27.  Find the standard form of the equation of each hyperbola satisfying the given conditions.

Center: (4, -2)
Focus: (7, -2)
Vertex: (6, -2)

A. (x - 4)2/4 - (y + 2)2/5 = 1

B. (x - 4)2/7 - (y + 2)2/6 = 1

C. (x - 4)2/2 - (y + 2)2/6 = 1

D. (x - 4)2/3 - (y + 2)2/4 = 1

 

28.  Find the vertices and locate the foci of each hyperbola with the given equation.

y2/4 - x2/1 = 1

A. Vertices at (0, 5) and (0, -5); foci at (0, 14) and (0, -14)

B. Vertices at (0, 6) and (0, -6); foci at (0, 13) and (0, -13)

C.  Vertices at (0, 2) and (0, -2); foci at (0, √5) and (0, -√5)

D. Vertices at (0, 1) and (0, -1); foci at (0, 12) and (0, -12)

 

 

 

29.  Find the standard form of the equation of the ellipse satisfying the given conditions.

Endpoints of major axis: (7, 9) and (7, 3)
Endpoints of minor axis: (5, 6) and (9, 6)

A. (x - 7)2/6 + (y - 6)2/7 = 1

B. (x - 7)2/5 + (y - 6)2/6 = 1

C. (x - 7)2/4 + (y - 6)2/9 = 1

D. (x - 5)2/4 + (y - 4)2/9 = 1

 

 

30.  Find the focus and directrix of the parabola with the given equation.

8x2 + 4y = 0

A. Focus: (0, -1/4); directrix: y = 1/4

B. Focus: (0, -1/6); directrix: y = 1/6

C. Focus: (0, -1/8); directrix: y = 1/8

D. Focus: (0, -1/2); directrix: y = ½

 

 

31.  Locate the foci and find the equations of the asymptotes.
 
x2/9 - y2/25 = 1

A. Foci: ({±√36, 0) ;asymptotes: y = ±5/3x

B. Foci: ({±√38, 0) ;asymptotes: y = ±5/3x

C. Foci: ({±√34, 0) ;asymptotes: y = ±5/3x

D. Foci: ({±√54, 0) ;asymptotes: y = ±6/3x

 

 

32.  Find the standard form of the equation of each hyperbola satisfying the given conditions.

Endpoints of transverse axis: (0, -6), (0, 6)
Asymptote: y = 2x

A. y2/6 - x2/9 = 1

B. y2/36 - x2/9 = 1

C. y2/37 - x2/27 = 1

D. y2/9 - x2/6 = 1

 

 

 

33.  Convert each equation to standard form by completing the square on x and y.

4x2 + y2 + 16x - 6y - 39 = 0

A. (x + 2)2/4 + (y - 3)2/39 = 1

B. (x + 2)2/39 + (y - 4)2/64 = 1

C. (x + 2)2/16 + (y - 3)2/64 = 1

D. (x + 2)2/6 + (y - 3)2/4 = 1

 

 

 

34.  Find the standard form of the equation of the following ellipse satisfying the given conditions.

Foci: (0, -4), (0, 4)
Vertices: (0, -7), (0, 7)

A. x2/43 + y2/28 = 1

B. x2/33 + y2/49 = 1

C. x2/53 + y2/21 = 1

D. x2/13 + y2/39 = 1

 

 

35.  Locate the foci of the ellipse of the following equation.
 
7x2 = 35 - 5y2

A. Foci at (0, -√2) and (0, √2)

B. Foci at (0, -√1) and (0, √1)

C. Foci at (0, -√7) and (0, √7)

D. Foci at (0, -√5) and (0, √5)

 

 

36.  Convert each equation to standard form by completing the square on x or y. Then find the vertex, focus, and directrix of the parabola.

y2 - 2y + 12x - 35 = 0

A. (y - 2)2 = -10(x - 3); vertex: (3, 1); focus: (0, 1); directrix: x = 9

B. (y - 1)2 = -12(x - 3); vertex: (3, 1); focus: (0, 1); directrix: x = 6

C. (y - 5)2 = -14(x - 3); vertex: (2, 1); focus: (0, 1); directrix: x = 6

D. (y - 2)2 = -12(x - 3); vertex: (3, 1); focus: (0, 1); directrix

 

 

37.  Convert each equation to standard form by completing the square on x or y. Then find the vertex, focus, and directrix of the parabola.

x2 - 2x - 4y + 9 = 0

A. (x - 4)2 = 4(y - 2); vertex: (1, 4); focus: (1, 3) ; directrix: y = 1

B. (x - 2)2 = 4(y - 3); vertex: (1, 2); focus: (1, 3) ; directrix: y = 3

C. (x - 1)2 = 4(y - 2); vertex: (1, 2); focus: (1, 3) ; directrix: y = 1

D. (x - 1)2 = 2(y - 2); vertex: (1, 3); focus: (1, 2) ; directrix: y=5

 

 

38.  Find the focus and directrix of each parabola with the given equation.

y2 = 4x

A. Focus: (2, 0); directrix: x = -1

B. Focus: (3, 0); directrix: x = -1

C. Focus: (5, 0); directrix: x = -1

D. Focus: (1, 0); directrix: x = -1

 

39.  Locate the foci of the ellipse of the following equation.

x2/16 + y2/4 = 1

A. Foci at (-2√3, 0) and (2√3, 0)

B. Foci at (5√3, 0) and (2√3, 0)

C. Foci at (-2√3, 0) and (5√3, 0)

D. Foci at (-7√2, 0) and (5√2,0)

 

40.  Find the standard form of the equation of each hyperbola satisfying the given conditions.

Foci: (0, -3), (0, 3)
Vertices: (0, -1), (0, 1)

A. y2 - x2/4 = 0

B. y2 - x2/8 = 1

C. y2 - x2/3 = 1

D. y2 - x2/2 = 0