Answers:
- 11) D. $30
- 12) Two answers: choice C, choice D
- 13) A. Subtract 100 from each side
- 14) A. n = 9 and n = -5
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Step-by-step explanation:
- 11) We set p(120-4p) equal to zero to find that p = 0 is one solution and 120-4p = 0 leads to p = 30. The prices of $0 and $30 both lead to $0 in revenue. It sounds like your teacher wants the larger price value.
- 12) We set each of the two revenue expressions equal to 600.
- 13) Replace the (n-2)^2 with another variable. Let's call that x. So we have the equation 100+x = 149, which is the same as x+100 = 149. We subtract 100 from both sides to undo the +100.
- 14) After following the steps in problem 13, you should have (n-2)^2 = 49, which then becomes n-2 = 7 or n-2 = -7 after applying the square root to both sides. Those two equations solve to n = 9 and n = -5 in that order.