Answer:
A
Step-by-step explanation:
Answer:
The answers are in the question.
Step-by-step explanation:
The wording can be off-putting but the answers are mostly there for you. It says that when the wind was at the tail of the plane, the travel was hastened to 5 hours instead of six. Is the rate of speed with the wind in favor of the plane is r+21, then it stands to reason that traveling AGAINST the wind will cause the rate to drop to r-21. Taking the average of the two travel times (5 and 6 hours each), we get 5.5 hours. Since speed is distance divided by time, the speed of the plane in still air will be <em>d</em> / 5.5
Be sure to label the speed as mph.
x + 7 = 2(3x - 4) Remove the brackets
x + 7 = 2*3x - 4*2
x + 7 = 6x - 8 Subtract 7 from both sides.
x + 7 - 7 = 6x - 8 - 7
x = 6x - 15 Subtract 6x from both sides
x - 6x = - 15
-5x = - 15 Divide by -5
-5x/-5 = -15/-5
x = 3
