It takes 4.3 seconds for the rocket to return to earth.
The equation is:

where -9.8m/sec² is the acceleration due to gravity, v₀ is the initial velocity, and h₀ is the initial height. We will go from the assumption that the rocket is launched from the ground, so h₀=0, and we are told that the initial velocity, v₀, is 42. This gives us:

We will use the quadratic formula to solve this. The quadratic formula is:

Plugging in our information we have:

x=0 is when the rocket is launched; x=4.3 is when the rocket lands.
Multiplying a negative number and another negative number makes the product positive.
So (-2.1)*(-1.4) = 2.94
Answer:
The actual distance between the historical markers is 18 miles.
Step-by-step explanation:
Given : On a map, the distance between two historical markers is 4.5 inches, and 2.5 inches represents 10 miles.
To find : What is the actual distance between the historical markers?
Solution :
We have given that,
2.5 inches represents 10 miles.
i.e, 1 inch represent
miles.
1 inch = 4 miles.
Now, The distance between two historical markers is 4.5 inches.
The actual distance between the historical markers in 4.5 inch is


Therefore, The actual distance between the historical markers is 18 miles.
Parenthasees
the first onewould evaluate to 4x²
the 2nd one would just be -2x²