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1. |
The temperature f(x) of water in a lake in degrees Fahrenheit is estimated by the function shown below, where x is the depth in feet of the water. What would be the temperature of water 30 feet below the surface? |
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A. |
111°F |
B. |
33°F |
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C. |
71.25°F |
D. |
63°F |
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Hint |
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2. |
Use the elimination method to solve the system of equations. 
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A. |
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B. |
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C. |
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D. |
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Hint |
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3. |
Use Cramer's rule to find the value of n in the system of equations. 
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A. |
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B. |
-22 |
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C. |
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D. |
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Hint |
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4. |
Use Cramer's rule to solve the system of equations. 
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A. |
(0.011, 0.0055) |
B. |
(0.4, 0.2) |
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C. |
(-0.4, -0.2) |
D. |
(0.2, 0.4) |
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Hint |
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5. |
Selena has 31 days to complete her quilt for the county fair. The blue squares in the quilt can be sewn at a rate of 4 squares per day, and the white squares at a rate of 7 squares per day. The quilt can have up to 96 squares total. The blue fabric b costs about $0.80 per square and the white fabric w costs about $1.20 per square. Selena wants to keep costs at a minimum. Write an inequality that expresses the total number of squares to be sewn. |
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A. |
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B. |
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C. |
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D. |
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Hint |
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6. |
Find the inverse of  |
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A. |
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B. |
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C. |
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D. |
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Hint |
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7. |
Write the matrix equation  as a system of linear equations. |
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A. |
-2s + t = 7
5s + 8t = 12 |
B. |
-2s = 7
5t = 12 |
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C. |
-2s + 5t = 7
s + 8t = 12 |
D. |
-2s + t = 12
5s + 8t = 7 |
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Hint |
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8. |
Simplify  |
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A. |
2i |
B. |
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C. |
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D. |
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Hint |
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9. |
Find the product of -15i and its conjugate. |
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A. |
225i |
B. |
225 |
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C. |
-225 |
D. |
15i |
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Hint |
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10. |
Simplify  |
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A. |
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B. |
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C. |
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D. |
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Hint |
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11. |
The graph of the equation -x2 + 4y2 - 10x - 8y - 29 = 0 is a(n) _____. |
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A. |
hyperbola |
B. |
circle |
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C. |
parabola |
D. |
ellipse |
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Hint |
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12. |
Solve the equation n2 +3n = 0 by graphing. |
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A. |
0, -3 |
B. |
0 |
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C. |
3 |
D. |
0, 3 |
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Hint |
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13. |
Solve x2 + 2x - 15 > 0. |
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A. |
{x | -5 < x < 3} |
B. |
{x | x < -3 or x > 5} |
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C. |
-3, 5 |
D. |
{x | x < -5 or x > 3} |
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Hint |
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14. |
If y varies directly as x and y = 2 when x = 4, find x when y = 4. |
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A. |
2 |
B. |
8 |
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C. |
16 |
D. |
4 |
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Hint |
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15. |
Solve the equation  |
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A. |
20 |
B. |
-1 |
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C. |
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D. |
9 |
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Hint |
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16. |
What is always true of an n × n matrix? |
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A. |
It is a row matrix. |
B. |
It is a square matrix. |
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C. |
It has at least two rows and two columns. |
D. |
It is a column matrix. |
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Hint |
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17. |
Find the area of a triangle whose vertices are located at (-3, 2), (0, -5), and (4, 4). |
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A. |
55 |
B. |
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C. |
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D. |
1 |
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Hint |
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18. |
Determine whether the pair of matrices  are inverses. |
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A. |
no, because A · B  I |
B. |
yes, because each entry in the second matrix is the reciprocal of its corresponding entry in the first matrix. |
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C. |
yes, because A · B = I. |
D. |
no, because fractions cannot be a part of an inverse |
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Hint |
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19. |
Simplify  |
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A. |
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B. |
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C. |
t |
D. |
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Hint |
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20. |
What is the equation of the parabola whose vertex is at (-3, 1) and passes through the point (-2, 4)? |
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A. |
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B. |
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C. |
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D. |
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Hint |
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