algebra 40

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1 of 40

2.5 Points

Use Cramer’s Rule to solve the following system.  

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x + 2y = 3  3x - 4y = 4

 

A. {(3, 1/5)}

 

B. {(5, 1/3)}

 

C. {(1, 1/2)}

 

D. {(2, 1/2)}

 2 of 40

2.5 Points

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

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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)}

3 of 40

2.5 Points

Use Cramer’s Rule to solve the following system.

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2x = 3y + 2  5x = 51 - 4y

 

A. {(8, 2)}

 

B. {(3, -4)}

 

C. {(2, 5)}

 

D. {(7, 4)}

4 of 40

2.5 Points

Use Cramer’s Rule to solve the following system.  

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4x - 5y = 17  2x + 3y = 3

 

A. {(3, -1)}

 

B. {(2, -1)}

 

C. {(3, -7)}

 

D. {(2, 0)}

 5 of 40

2.5 Points

Use Cramer’s Rule to solve the following system.

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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)}

 6 of 40

2.5 Points

Use Cramer’s Rule to solve the following system.

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3x - 4y = 4  2x + 2y = 12

 

A. {(3, 1)}

 

B. {(4, 2)}

 

C. {(5, 1)}

 

D. {(2, 1)}

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 7 of 40

2.5 Points

Use Cramer’s Rule to solve the following system.

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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)}

8 of 40

2.5 Points

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

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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)}

 9 of 40

2.5 Points

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

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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)}

10 of 40

2.5 Points

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

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

The inverse of:

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2 2 2

  6 7 7

  6 6 7

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is

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7/2 -1 0

  0 1 -1

  -3 0 1

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

 

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

 

C. {(1, 2, 0)}

 

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

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 11 of 40

2.5 Points

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

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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)}

 12 of 40

2.5 Points

Use Cramer’s Rule to solve the following system.  

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x + y = 7  x - y = 3

 

A. {(7, 2)}

 

B. {(8, -2)}

 

C. {(5, 2)}

 

D. {(9, 3)}

13 of 40

2.5 Points

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

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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)}

 14 of 40

2.5 Points

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

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2x  z

  y + 7  4

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 = 

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-10 6

  13 4

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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

 15 of 40

2.5 Points

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

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5x + 8y - 6z = 14  3x + 4y - 2z = 8  x + 2y - 2z = 3

 

A. {(-4t + 2, 2t + 1/2, t)}

 

B. {(-3t + 1, 5t + 1/3, t)}

 

C. {(2t + -2, t + 1/2, t)}

 

D. {(-2t + 2, 2t + 1/2, t)}

16 of 40

2.5 Points

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

Are A =

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0 1

  -1 0

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and B =

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1 0

0   -1

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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

 17 of 40

2.5 Points

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

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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)}

18 of 40

2.5 Points

Use Gauss-Jordan elimination to solve the system.

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-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 of 40

2.5 Points

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

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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)}

20 of 40

2.5 Points

Find the products AB and BA to determine whether B is the multiplicative inverse of A. 

A =

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0 0 1

1 0   0

0 1   0

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B =

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0 1 0

0 0   1

1 0   0

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A. AB = I; BA = I3; B = A

 

B. AB = I3; BA = I3; B = A-1

 

C. AB = I; AB = I3; B = A-1

 

D. AB = I3; BA = I3; A = B-1

 21 of 40

2.5 Points

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

22 of 40

2.5 Points

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: x = 8

23 of 40

2.5 Points

Convert each equation to standard form by completing the square on x and y. 9x2 + 16y2 - 18x + 64y - 71 = 0

 

A. (x - 1)2/9 + (y + 2)2/18 = 1

 

B. (x - 1)2/18 + (y + 2)2/71 = 1

 

C. (x - 1)2/16 + (y + 2)2/9 = 1

 

D. (x - 1)2/64 + (y + 2)2/9 = 1

24 of 40

2.5 Points

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

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25 of 40

2.5 Points

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

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 26 of 40

2.5 Points

Find the standard form of the equation of the ellipse satisfying the given conditions. Major axis vertical with length = 10 Length of minor axis = 4 Center: (-2, 3)

 

A. (x + 2)2/4 + (y - 3)2/25 = 1

 

B. (x + 4)2/4 + (y - 2)2/25 = 1

 

C. (x + 3)2/4 + (y - 2)2/25 = 1

 

D. (x + 5)2/4 + (y - 2)2/25 = 1

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 27 of 40

2.5 Points

Find the vertices and locate the foci of each hyperbola with the given equation. x2/4 - y2/1 =1

 

A.

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

 

B.

Vertices at (3, 0) and (-3 0); foci at (12, 0) and (-12, 0)

 

C. Vertices at (4, 0) and (-4, 0); foci at (16, 0) and (-16, 0)

 

D. Vertices at (5

28 of 40

2.5 Points

Locate the foci of the ellipse of the following equation. 25x2 + 4y2 = 100

 

A. Foci at (1, -√11) and (1, √11)

 

B. Foci at (0, -√25) and (0, √25)

 

C. Foci at (0, -√22) and (0, √22)

 

D. Foci at (0, -√21) and (0, √21)

29 of 40

2.5 Points

Find the vertex, focus, and directrix of each parabola with the given equation. (x - 2)2 = 8(y - 1)

 

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

 

B. Vertex: (2, 1); focus: (2, 3); directrix: y = -1

 

C. Vertex: (1, 1); focus: (2, 4); directrix: y = -1

 

D. Vertex: (2, 3); 

 30 of 40

2.5 Points

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

31 of 40

2.5 Points

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)

32 of 40

2.5 Points

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)

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33 of 40

2.5 Points

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

33 of 40

2.5 Points

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 of 40

2.5 Points

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

 36 of 40

2.5 Points

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

 37 of 40

2.5 Points

Locate the foci and find the equations of the asymptotes.   4y2 – x2 = 1

 

A. (0, ±√4/2); asymptotes: y = ±1/3x

 

B. (0, ±√5/2); asymptotes: y = ±1/2x

 

C. (0, ±√5/4); asymptotes: y = ±1/3x

 

D. (0, ±√5/3); asymptotes: y = ±1/2x

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38 of 40

2.5 Points

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

39 of 40

2.5 Points

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

 40 of 40

2.5 Points

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