91Ó°ÊÓ

Solve each quadratic inequality. Write each solution set in interval notation. $$-x^{2}-6 x-16>-8$$

Solve each quadratic inequality. Write each solution set in interval notation. $$x^{2} \leq 9$$

Find each sum or difference. Write the answer in standard form. $$(2-5 i)-(3+4 i)-(-2+i)$$

Solve each quadratic inequality. Write each solution set in interval notation. $$x^{2}>16$$

Francisco claimed that the equation \(x^{2}-8 x=0\) cannot be solved by the quadratic formula since there is no value for \(c .\) Is he correct?

Find each product. Write the answer in standard form. $$(2+i)(3-2 i)$$

If p units of an item are sold for \(x\) dollars per unit, the revenue is \(R=p x\). Use this idea to analyze the following problem. Number of Apartments Rented The manager of an 80-unit apartment complex knows from experience that at a rent of \(\$ 300,\) all the units will be full. On the average, one additional unit will remain vacant for each \(\$ 20\) increase in rent over \(\$ 300 .\) Furthermore, the manager must keep at least 30 units rented due to other financial considerations. Currently, the revenue from the complex is \(\$ 35,000 .\) How many apartments are rented? Suppose that \(x\) represents the number of \(\$ 20\) increases over \(\$ 300 .\) Represent the number of apartment units that will be rented in terms of \(x .\)

Which one of the following inequalities has solution set \((-\infty, \infty) ?\) A. \((x-3)^{2} \geq 0\) B. \((5 x-6)^{2} \leq 0\) C. \((6 x+4)^{2}>0\) D. \((8 x+7)^{2}<0\)

The cost of a charter flight to Miami is \(\$ 225\) each for 75 passengers, with a refund of \(\$ 5\) per passenger for each passenger in excess of \(75 .\) How many passengers must take the flight to produce a revenue of \(\$ 16,000 ?\)

Celsius and Fahrenheit Temperatures In the met- ric system of weights and measures, temperature is measured in degrees Celsius (" \(^{\circ}\) C) instead of degrees Fahrenheit \(\left(^{\circ} \mathrm{F}\right) .\) To convert between the two systems, we use the equations $$ C=\frac{5}{9}(F-32) \quad \text { and } \quad F=\frac{9}{5} C+32 $$ In each exercise, convert to the other system. Round answers to the nearest tenth of a degree if necessary. $$40^{\circ} \mathrm{C}$$