Respuesta :
Answer:
108 seconds.
Step-by-step explanation:
Let x represent number of seconds.
We have been given that a hot- air balloon is rising from the ground at a rate of 4 feet every second. So altitude of hot-air balloon would be [tex]4x[/tex] feet after x seconds.
We are also told that another balloon at 756 feet is descending at a rate of 3 feet every second. Since the altitude of 2nd balloon is descending, so altitude after x seconds would be initial altitude minus change in altitude after x seconds [tex]756-3x[/tex].
Now, we will equate both expression to find the time as:
[tex]4x=756-3x[/tex]
[tex]4x+3x=756-3x+3x[/tex]
[tex]7x=756[/tex]
[tex]\frac{7x}{7}=\frac{756}{7}[/tex]
[tex]x=108[/tex]
Therefore, the two balloons will be at the same altitude in 108 seconds.
