264 Chapter 3 Systems of Linear Equations and Inequalities TIP: To check Example 3, note that $11,000 is twice $5500. Furthermore, ° ✔ Amount earned from 4.5% account 4. Applications Involving Uniform Motion Solving a Distance, Rate, and Time Application A plane flies 660 mi from Atlanta to Miami in 1.2 hr when traveling with a tailwind. The return flight against the same wind takes 1.5 hr. Find the speed of the plane in still air and the speed of the wind. Solution: Let p represent the speed of the plane in still air. Let w represent the speed of the wind. The speed of the plane with the wind: (Plane’s still airspeed) (wind speed) The speed of the plane against the wind: (Plane’s still airspeed) (wind speed) Set up a chart to organize the given information: p w p w Example 4 ¢ ° amount earned from 7% account ¢ $550010.0452 $11,00010.072 1017.50 Distance Rate Time With a tailwind 660 p w 1.2 Against the wind 660 p w 1.5 Two equations can be found by using the relationship . ° Distance against wind ¢ ° speed against wind 660 1p w211.22 660 1p w211.52 Divide by 1.5. 660 1.5 d rt 1p w21.5 1.5 440 p w 660 1p w211.22 Divide by 1. 2. 660 1.2 1p w21.2 1.2 550 p w 660 1p w211.52 ¢ ° time against wind ¢ 660 1p w211.52 ° Distance with wind ¢ ° speed with wind ¢ ° time with wind ¢ 660 1p w211.22 Notice that the first equation may be divided by 1.2 and still leave integer coefficients. Similarly, the second equation may be simplified by dividing by 1.5. TIP: In Section 3.3 we used the multiplication property of equality to create opposite coefficients. Example 4 demonstrates that we can also use the division property of equality to create opposite coefficients.
miller_intermediate_algebra_4e_ch1_3
To see the actual publication please follow the link above