Answer:
1. 58 seconds
2. 5834.5 feet
Step-by-step explanation:
The equation [tex]A(t) = 40.25t + 3500[/tex] can be used to represent the height of plane A at time t seconds. Similarly, the equation [tex]B(t) = 55.75t + 2601[/tex] represents the height of plane B after t seconds. To solve for when the planes are at the same height, we can set these two equations equal to get [tex]40.25t + 3500 = 55.75t + 2601 \Rightarrow 15.5t = 899 \Rightarrow t = 58.[/tex] So, [tex]\boxed{\boxed {58}}[/tex] seconds will pass before the planes are at the same altitude. Plugging in t=58 into either of the equations, we see their altitudes will be [tex]\boxed{\text{5834.5 feet}}[/tex] .