9. A birdhouse sits on top of a pole. A wire attached 3 ft below the top of the pole is attached to an anchor, which is 12 ft from the bottom of the pole. If the hypotenuse of the right triangle formed by the pole, wire, and ground is 18 ft long, find the height of the pole. Round your answer to one place.
11. The hypotenuse of a right triangle is 6 ft longer than the shortest side. If the sum of the lengths of the two legs is 21 ft, find the lengths of all three sides.
19. Use the graph of the related parabola to estimate the solutions to 0 = x2 + 5x +1. Round answers to three places.
A) {0.209, 4.791}
B) {–4.791, –0.209}
C) {–2.5, 2.5)
D) {–2.291, 2.291}
20. A rectangular room has an area of 108 square feet and a perimeter of 43 feet. What are the dimensions of the room? Find the exact solution.
21. A small company's weekly profit P, in dollars, is related to the number of items sold x by P(x) = –0.4x2 + 80x + 1250. Find the number of items that should be sold each week in order to maximize the profit. Then find the amount of that weekly profit.
A) 40 items, $3,810
B) 80 items, $5,090
C) 100 items, $5,250
D) 200 items, $57,250
22. Solve the inequality graphically and graph the solution set on a number line.
(x + 7)(x – 3) < 0
25. Solve the inequality algebraically and graph the solution set on a number line.
x2 – 36 <=0