Solve the problem.In his algebra class, Rob has scores of 79, 85, 81, and 65 on his first four tests. To get a grade of C, the average of the first five tests must be greater than or equal to 70 and less than 80. Solve an inequality to find the range of scores that Rob can earn on the fifth test to get a C.
A. x ? 40, where x represents Bob's score on the fifth test
B. 40 ? x < 90, where x represents Bob's score on the fifth test
C. 40 < x < 90, where x represents Bob's score on the fifth test
D. 40 ? x ? 90, where x represents Bob's score on the fifth test
Answer: B
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Determine whether the statement is true or false. {2, 9} ? {9, 2}
A. True B. False
Provide an appropriate response.True or false? If a > 0, then 
= ia.
A. True B. False
Approximate the expression to the nearest thousandth.
A. 24.018 B. -22.006 C. 22.006 D. -24.017
Solve the problem.An agricultural research scientist is developing three new crop growth supplements -- A, B, and C. Each pound of each supplement contains four enzymes -- E1, E2, E3, and E4 -- in the amounts (in milligrams) shown in the table.
The cost of E1 is $20/mg, the cost of E2 is $40/mg, the cost of E3 is $10/mg, and the cost of E4 is also $10/mg. The growth benefit for crops is expected to be proportional to 10 times the amount of A used, 25 times the amount of B used, and 60 times the amount of C used. However, the total cost of the enzymes used in A, B, and C must be less than $5000 for each treatment. How many pounds each of A, B, and C should be produced to maximize
the growth effect? A.
| 0, 9.3, 10.0 |
B. 0, 0, 15
C. 9.0, 0, 9.5
D. 3.0, 3.0, 4.0